unittests/ADT/StringRefTest.cpp

   1 //===- llvm/unittest/ADT/StringRefTest.cpp - StringRef unit tests ---------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "llvm/ADT/StringRef.h"
  10 #include "llvm/ADT/Hashing.h"
  11 #include "llvm/ADT/STLExtras.h"
  12 #include "llvm/ADT/SmallVector.h"
  13 #include "llvm/ADT/StringExtras.h"
  14 #include "llvm/Support/Allocator.h"
  15 #include "llvm/Support/raw_ostream.h"
  16 #include "gtest/gtest.h"
  17 using namespace llvm;
  18
  19 namespace llvm {
  20
  21 std::ostream &operator<<(std::ostream &OS, const StringRef &S) {
  22   OS << S.str();
  23   return OS;
  24 }
  25
  26 std::ostream &operator<<(std::ostream &OS,
  27                          const std::pair<StringRef, StringRef> &P) {
  28   OS << "(" << P.first << ", " << P.second << ")";
  29   return OS;
  30 }
  31
  32 }
  33
  34 // Check that we can't accidentally assign a temporary std::string to a
  35 // StringRef. (Unfortunately we can't make use of the same thing with
  36 // constructors.)
  37 static_assert(
  38     !std::is_assignable<StringRef&, std::string>::value,
  39     "Assigning from prvalue std::string");
  40 static_assert(
  41     !std::is_assignable<StringRef&, std::string &&>::value,
  42     "Assigning from xvalue std::string");
  43 static_assert(
  44     std::is_assignable<StringRef&, std::string &>::value,
  45     "Assigning from lvalue std::string");
  46 static_assert(
  47     std::is_assignable<StringRef&, const char *>::value,
  48     "Assigning from prvalue C string");
  49 static_assert(
  50     std::is_assignable<StringRef&, const char * &&>::value,
  51     "Assigning from xvalue C string");
  52 static_assert(
  53     std::is_assignable<StringRef&, const char * &>::value,
  54     "Assigning from lvalue C string");
  55
  56 namespace {
  57 TEST(StringRefTest, Construction) {
  58   EXPECT_EQ("", StringRef());
  59   EXPECT_EQ("hello", StringRef("hello"));
  60   EXPECT_EQ("hello", StringRef("hello world", 5));
  61   EXPECT_EQ("hello", StringRef(std::string("hello")));
  62 }
  63
  64 TEST(StringRefTest, EmptyInitializerList) {
  65   StringRef S = {};
  66   EXPECT_TRUE(S.empty());
  67
  68   S = {};
  69   EXPECT_TRUE(S.empty());
  70 }
  71
  72 TEST(StringRefTest, Iteration) {
  73   StringRef S("hello");
  74   const char *p = "hello";
  75   for (const char *it = S.begin(), *ie = S.end(); it != ie; ++it, ++p)
  76     EXPECT_EQ(*it, *p);
  77 }
  78
  79 TEST(StringRefTest, StringOps) {
  80   const char *p = "hello";
  81   EXPECT_EQ(p, StringRef(p, 0).data());
  82   EXPECT_TRUE(StringRef().empty());
  83   EXPECT_EQ((size_t) 5, StringRef("hello").size());
  84   EXPECT_EQ(-1, StringRef("aab").compare("aad"));
  85   EXPECT_EQ( 0, StringRef("aab").compare("aab"));
  86   EXPECT_EQ( 1, StringRef("aab").compare("aaa"));
  87   EXPECT_EQ(-1, StringRef("aab").compare("aabb"));
  88   EXPECT_EQ( 1, StringRef("aab").compare("aa"));
  89   EXPECT_EQ( 1, StringRef("\xFF").compare("\1"));
  90
  91   EXPECT_EQ(-1, StringRef("AaB").compare_lower("aAd"));
  92   EXPECT_EQ( 0, StringRef("AaB").compare_lower("aab"));
  93   EXPECT_EQ( 1, StringRef("AaB").compare_lower("AAA"));
  94   EXPECT_EQ(-1, StringRef("AaB").compare_lower("aaBb"));
  95   EXPECT_EQ(-1, StringRef("AaB").compare_lower("bb"));
  96   EXPECT_EQ( 1, StringRef("aaBb").compare_lower("AaB"));
  97   EXPECT_EQ( 1, StringRef("bb").compare_lower("AaB"));
  98   EXPECT_EQ( 1, StringRef("AaB").compare_lower("aA"));
  99   EXPECT_EQ( 1, StringRef("\xFF").compare_lower("\1"));
 100
 101   EXPECT_EQ(-1, StringRef("aab").compare_numeric("aad"));
 102   EXPECT_EQ( 0, StringRef("aab").compare_numeric("aab"));
 103   EXPECT_EQ( 1, StringRef("aab").compare_numeric("aaa"));
 104   EXPECT_EQ(-1, StringRef("aab").compare_numeric("aabb"));
 105   EXPECT_EQ( 1, StringRef("aab").compare_numeric("aa"));
 106   EXPECT_EQ(-1, StringRef("1").compare_numeric("10"));
 107   EXPECT_EQ( 0, StringRef("10").compare_numeric("10"));
 108   EXPECT_EQ( 0, StringRef("10a").compare_numeric("10a"));
 109   EXPECT_EQ( 1, StringRef("2").compare_numeric("1"));
 110   EXPECT_EQ( 0, StringRef("llvm_v1i64_ty").compare_numeric("llvm_v1i64_ty"));
 111   EXPECT_EQ( 1, StringRef("\xFF").compare_numeric("\1"));
 112   EXPECT_EQ( 1, StringRef("V16").compare_numeric("V1_q0"));
 113   EXPECT_EQ(-1, StringRef("V1_q0").compare_numeric("V16"));
 114   EXPECT_EQ(-1, StringRef("V8_q0").compare_numeric("V16"));
 115   EXPECT_EQ( 1, StringRef("V16").compare_numeric("V8_q0"));
 116   EXPECT_EQ(-1, StringRef("V1_q0").compare_numeric("V8_q0"));
 117   EXPECT_EQ( 1, StringRef("V8_q0").compare_numeric("V1_q0"));
 118 }
 119
 120 TEST(StringRefTest, Operators) {
 121   EXPECT_EQ("", StringRef());
 122   EXPECT_TRUE(StringRef("aab") < StringRef("aad"));
 123   EXPECT_FALSE(StringRef("aab") < StringRef("aab"));
 124   EXPECT_TRUE(StringRef("aab") <= StringRef("aab"));
 125   EXPECT_FALSE(StringRef("aab") <= StringRef("aaa"));
 126   EXPECT_TRUE(StringRef("aad") > StringRef("aab"));
 127   EXPECT_FALSE(StringRef("aab") > StringRef("aab"));
 128   EXPECT_TRUE(StringRef("aab") >= StringRef("aab"));
 129   EXPECT_FALSE(StringRef("aaa") >= StringRef("aab"));
 130   EXPECT_EQ(StringRef("aab"), StringRef("aab"));
 131   EXPECT_FALSE(StringRef("aab") == StringRef("aac"));
 132   EXPECT_FALSE(StringRef("aab") != StringRef("aab"));
 133   EXPECT_TRUE(StringRef("aab") != StringRef("aac"));
 134   EXPECT_EQ('a', StringRef("aab")[1]);
 135 }
 136
 137 TEST(StringRefTest, Substr) {
 138   StringRef Str("hello");
 139   EXPECT_EQ("lo", Str.substr(3));
 140   EXPECT_EQ("", Str.substr(100));
 141   EXPECT_EQ("hello", Str.substr(0, 100));
 142   EXPECT_EQ("o", Str.substr(4, 10));
 143 }
 144
 145 TEST(StringRefTest, Slice) {
 146   StringRef Str("hello");
 147   EXPECT_EQ("l", Str.slice(2, 3));
 148   EXPECT_EQ("ell", Str.slice(1, 4));
 149   EXPECT_EQ("llo", Str.slice(2, 100));
 150   EXPECT_EQ("", Str.slice(2, 1));
 151   EXPECT_EQ("", Str.slice(10, 20));
 152 }
 153
 154 TEST(StringRefTest, Split) {
 155   StringRef Str("hello");
 156   EXPECT_EQ(std::make_pair(StringRef("hello"), StringRef("")),
 157             Str.split('X'));
 158   EXPECT_EQ(std::make_pair(StringRef("h"), StringRef("llo")),
 159             Str.split('e'));
 160   EXPECT_EQ(std::make_pair(StringRef(""), StringRef("ello")),
 161             Str.split('h'));
 162   EXPECT_EQ(std::make_pair(StringRef("he"), StringRef("lo")),
 163             Str.split('l'));
 164   EXPECT_EQ(std::make_pair(StringRef("hell"), StringRef("")),
 165             Str.split('o'));
 166
 167   EXPECT_EQ(std::make_pair(StringRef("hello"), StringRef("")),
 168             Str.rsplit('X'));
 169   EXPECT_EQ(std::make_pair(StringRef("h"), StringRef("llo")),
 170             Str.rsplit('e'));
 171   EXPECT_EQ(std::make_pair(StringRef(""), StringRef("ello")),
 172             Str.rsplit('h'));
 173   EXPECT_EQ(std::make_pair(StringRef("hel"), StringRef("o")),
 174             Str.rsplit('l'));
 175   EXPECT_EQ(std::make_pair(StringRef("hell"), StringRef("")),
 176             Str.rsplit('o'));
 177
 178   EXPECT_EQ(std::make_pair(StringRef("he"), StringRef("o")),
 179                     Str.rsplit("ll"));
 180   EXPECT_EQ(std::make_pair(StringRef(""), StringRef("ello")),
 181                     Str.rsplit("h"));
 182   EXPECT_EQ(std::make_pair(StringRef("hell"), StringRef("")),
 183               Str.rsplit("o"));
 184   EXPECT_EQ(std::make_pair(StringRef("hello"), StringRef("")),
 185                     Str.rsplit("::"));
 186   EXPECT_EQ(std::make_pair(StringRef("hel"), StringRef("o")),
 187                     Str.rsplit("l"));
 188 }
 189
 190 TEST(StringRefTest, Split2) {
 191   SmallVector<StringRef, 5> parts;
 192   SmallVector<StringRef, 5> expected;
 193
 194   expected.push_back("ab"); expected.push_back("c");
 195   StringRef(",ab,,c,").split(parts, ",", -1, false);
 196   EXPECT_TRUE(parts == expected);
 197
 198   expected.clear(); parts.clear();
 199   expected.push_back(""); expected.push_back("ab"); expected.push_back("");
 200   expected.push_back("c"); expected.push_back("");
 201   StringRef(",ab,,c,").split(parts, ",", -1, true);
 202   EXPECT_TRUE(parts == expected);
 203
 204   expected.clear(); parts.clear();
 205   expected.push_back("");
 206   StringRef("").split(parts, ",", -1, true);
 207   EXPECT_TRUE(parts == expected);
 208
 209   expected.clear(); parts.clear();
 210   StringRef("").split(parts, ",", -1, false);
 211   EXPECT_TRUE(parts == expected);
 212
 213   expected.clear(); parts.clear();
 214   StringRef(",").split(parts, ",", -1, false);
 215   EXPECT_TRUE(parts == expected);
 216
 217   expected.clear(); parts.clear();
 218   expected.push_back(""); expected.push_back("");
 219   StringRef(",").split(parts, ",", -1, true);
 220   EXPECT_TRUE(parts == expected);
 221
 222   expected.clear(); parts.clear();
 223   expected.push_back("a"); expected.push_back("b");
 224   StringRef("a,b").split(parts, ",", -1, true);
 225   EXPECT_TRUE(parts == expected);
 226
 227   // Test MaxSplit
 228   expected.clear(); parts.clear();
 229   expected.push_back("a,,b,c");
 230   StringRef("a,,b,c").split(parts, ",", 0, true);
 231   EXPECT_TRUE(parts == expected);
 232
 233   expected.clear(); parts.clear();
 234   expected.push_back("a,,b,c");
 235   StringRef("a,,b,c").split(parts, ",", 0, false);
 236   EXPECT_TRUE(parts == expected);
 237
 238   expected.clear(); parts.clear();
 239   expected.push_back("a"); expected.push_back(",b,c");
 240   StringRef("a,,b,c").split(parts, ",", 1, true);
 241   EXPECT_TRUE(parts == expected);
 242
 243   expected.clear(); parts.clear();
 244   expected.push_back("a"); expected.push_back(",b,c");
 245   StringRef("a,,b,c").split(parts, ",", 1, false);
 246   EXPECT_TRUE(parts == expected);
 247
 248   expected.clear(); parts.clear();
 249   expected.push_back("a"); expected.push_back(""); expected.push_back("b,c");
 250   StringRef("a,,b,c").split(parts, ",", 2, true);
 251   EXPECT_TRUE(parts == expected);
 252
 253   expected.clear(); parts.clear();
 254   expected.push_back("a"); expected.push_back("b,c");
 255   StringRef("a,,b,c").split(parts, ",", 2, false);
 256   EXPECT_TRUE(parts == expected);
 257
 258   expected.clear(); parts.clear();
 259   expected.push_back("a"); expected.push_back(""); expected.push_back("b");
 260   expected.push_back("c");
 261   StringRef("a,,b,c").split(parts, ",", 3, true);
 262   EXPECT_TRUE(parts == expected);
 263
 264   expected.clear(); parts.clear();
 265   expected.push_back("a"); expected.push_back("b"); expected.push_back("c");
 266   StringRef("a,,b,c").split(parts, ",", 3, false);
 267   EXPECT_TRUE(parts == expected);
 268
 269   expected.clear(); parts.clear();
 270   expected.push_back("a"); expected.push_back("b"); expected.push_back("c");
 271   StringRef("a,,b,c").split(parts, ',', 3, false);
 272   EXPECT_TRUE(parts == expected);
 273
 274   expected.clear(); parts.clear();
 275   expected.push_back("");
 276   StringRef().split(parts, ",", 0, true);
 277   EXPECT_TRUE(parts == expected);
 278
 279   expected.clear(); parts.clear();
 280   expected.push_back(StringRef());
 281   StringRef("").split(parts, ",", 0, true);
 282   EXPECT_TRUE(parts == expected);
 283
 284   expected.clear(); parts.clear();
 285   StringRef("").split(parts, ",", 0, false);
 286   EXPECT_TRUE(parts == expected);
 287   StringRef().split(parts, ",", 0, false);
 288   EXPECT_TRUE(parts == expected);
 289
 290   expected.clear(); parts.clear();
 291   expected.push_back("a");
 292   expected.push_back("");
 293   expected.push_back("b");
 294   expected.push_back("c,d");
 295   StringRef("a,,b,c,d").split(parts, ",", 3, true);
 296   EXPECT_TRUE(parts == expected);
 297
 298   expected.clear(); parts.clear();
 299   expected.push_back("");
 300   StringRef().split(parts, ',', 0, true);
 301   EXPECT_TRUE(parts == expected);
 302
 303   expected.clear(); parts.clear();
 304   expected.push_back(StringRef());
 305   StringRef("").split(parts, ',', 0, true);
 306   EXPECT_TRUE(parts == expected);
 307
 308   expected.clear(); parts.clear();
 309   StringRef("").split(parts, ',', 0, false);
 310   EXPECT_TRUE(parts == expected);
 311   StringRef().split(parts, ',', 0, false);
 312   EXPECT_TRUE(parts == expected);
 313
 314   expected.clear(); parts.clear();
 315   expected.push_back("a");
 316   expected.push_back("");
 317   expected.push_back("b");
 318   expected.push_back("c,d");
 319   StringRef("a,,b,c,d").split(parts, ',', 3, true);
 320   EXPECT_TRUE(parts == expected);
 321 }
 322
 323 TEST(StringRefTest, Trim) {
 324   StringRef Str0("hello");
 325   StringRef Str1(" hello ");
 326   StringRef Str2("  hello  ");
 327
 328   EXPECT_EQ(StringRef("hello"), Str0.rtrim());
 329   EXPECT_EQ(StringRef(" hello"), Str1.rtrim());
 330   EXPECT_EQ(StringRef("  hello"), Str2.rtrim());
 331   EXPECT_EQ(StringRef("hello"), Str0.ltrim());
 332   EXPECT_EQ(StringRef("hello "), Str1.ltrim());
 333   EXPECT_EQ(StringRef("hello  "), Str2.ltrim());
 334   EXPECT_EQ(StringRef("hello"), Str0.trim());
 335   EXPECT_EQ(StringRef("hello"), Str1.trim());
 336   EXPECT_EQ(StringRef("hello"), Str2.trim());
 337
 338   EXPECT_EQ(StringRef("ello"), Str0.trim("hhhhhhhhhhh"));
 339
 340   EXPECT_EQ(StringRef(""), StringRef("").trim());
 341   EXPECT_EQ(StringRef(""), StringRef(" ").trim());
 342   EXPECT_EQ(StringRef("\0", 1), StringRef(" \0 ", 3).trim());
 343   EXPECT_EQ(StringRef("\0\0", 2), StringRef("\0\0", 2).trim());
 344   EXPECT_EQ(StringRef("x"), StringRef("\0\0x\0\0", 5).trim('\0'));
 345 }
 346
 347 TEST(StringRefTest, StartsWith) {
 348   StringRef Str("hello");
 349   EXPECT_TRUE(Str.startswith(""));
 350   EXPECT_TRUE(Str.startswith("he"));
 351   EXPECT_FALSE(Str.startswith("helloworld"));
 352   EXPECT_FALSE(Str.startswith("hi"));
 353 }
 354
 355 TEST(StringRefTest, StartsWithLower) {
 356   StringRef Str("heLLo");
 357   EXPECT_TRUE(Str.startswith_lower(""));
 358   EXPECT_TRUE(Str.startswith_lower("he"));
 359   EXPECT_TRUE(Str.startswith_lower("hell"));
 360   EXPECT_TRUE(Str.startswith_lower("HELlo"));
 361   EXPECT_FALSE(Str.startswith_lower("helloworld"));
 362   EXPECT_FALSE(Str.startswith_lower("hi"));
 363 }
 364
 365 TEST(StringRefTest, ConsumeFront) {
 366   StringRef Str("hello");
 367   EXPECT_TRUE(Str.consume_front(""));
 368   EXPECT_EQ("hello", Str);
 369   EXPECT_TRUE(Str.consume_front("he"));
 370   EXPECT_EQ("llo", Str);
 371   EXPECT_FALSE(Str.consume_front("lloworld"));
 372   EXPECT_EQ("llo", Str);
 373   EXPECT_FALSE(Str.consume_front("lol"));
 374   EXPECT_EQ("llo", Str);
 375   EXPECT_TRUE(Str.consume_front("llo"));
 376   EXPECT_EQ("", Str);
 377   EXPECT_FALSE(Str.consume_front("o"));
 378   EXPECT_TRUE(Str.consume_front(""));
 379 }
 380
 381 TEST(StringRefTest, EndsWith) {
 382   StringRef Str("hello");
 383   EXPECT_TRUE(Str.endswith(""));
 384   EXPECT_TRUE(Str.endswith("lo"));
 385   EXPECT_FALSE(Str.endswith("helloworld"));
 386   EXPECT_FALSE(Str.endswith("worldhello"));
 387   EXPECT_FALSE(Str.endswith("so"));
 388 }
 389
 390 TEST(StringRefTest, EndsWithLower) {
 391   StringRef Str("heLLo");
 392   EXPECT_TRUE(Str.endswith_lower(""));
 393   EXPECT_TRUE(Str.endswith_lower("lo"));
 394   EXPECT_TRUE(Str.endswith_lower("LO"));
 395   EXPECT_TRUE(Str.endswith_lower("ELlo"));
 396   EXPECT_FALSE(Str.endswith_lower("helloworld"));
 397   EXPECT_FALSE(Str.endswith_lower("hi"));
 398 }
 399
 400 TEST(StringRefTest, ConsumeBack) {
 401   StringRef Str("hello");
 402   EXPECT_TRUE(Str.consume_back(""));
 403   EXPECT_EQ("hello", Str);
 404   EXPECT_TRUE(Str.consume_back("lo"));
 405   EXPECT_EQ("hel", Str);
 406   EXPECT_FALSE(Str.consume_back("helhel"));
 407   EXPECT_EQ("hel", Str);
 408   EXPECT_FALSE(Str.consume_back("hle"));
 409   EXPECT_EQ("hel", Str);
 410   EXPECT_TRUE(Str.consume_back("hel"));
 411   EXPECT_EQ("", Str);
 412   EXPECT_FALSE(Str.consume_back("h"));
 413   EXPECT_TRUE(Str.consume_back(""));
 414 }
 415
 416 TEST(StringRefTest, Find) {
 417   StringRef Str("helloHELLO");
 418   StringRef LongStr("hellx xello hell ello world foo bar hello HELLO");
 419
 420   struct {
 421     StringRef Str;
 422     char C;
 423     std::size_t From;
 424     std::size_t Pos;
 425     std::size_t LowerPos;
 426   } CharExpectations[] = {
 427       {Str, 'h', 0U, 0U, 0U},
 428       {Str, 'e', 0U, 1U, 1U},
 429       {Str, 'l', 0U, 2U, 2U},
 430       {Str, 'l', 3U, 3U, 3U},
 431       {Str, 'o', 0U, 4U, 4U},
 432       {Str, 'L', 0U, 7U, 2U},
 433       {Str, 'z', 0U, StringRef::npos, StringRef::npos},
 434   };
 435
 436   struct {
 437     StringRef Str;
 438     llvm::StringRef S;
 439     std::size_t From;
 440     std::size_t Pos;
 441     std::size_t LowerPos;
 442   } StrExpectations[] = {
 443       {Str, "helloword", 0, StringRef::npos, StringRef::npos},
 444       {Str, "hello", 0, 0U, 0U},
 445       {Str, "ello", 0, 1U, 1U},
 446       {Str, "zz", 0, StringRef::npos, StringRef::npos},
 447       {Str, "ll", 2U, 2U, 2U},
 448       {Str, "ll", 3U, StringRef::npos, 7U},
 449       {Str, "LL", 2U, 7U, 2U},
 450       {Str, "LL", 3U, 7U, 7U},
 451       {Str, "", 0U, 0U, 0U},
 452       {LongStr, "hello", 0U, 36U, 36U},
 453       {LongStr, "foo", 0U, 28U, 28U},
 454       {LongStr, "hell", 2U, 12U, 12U},
 455       {LongStr, "HELL", 2U, 42U, 12U},
 456       {LongStr, "", 0U, 0U, 0U}};
 457
 458   for (auto &E : CharExpectations) {
 459     EXPECT_EQ(E.Pos, E.Str.find(E.C, E.From));
 460     EXPECT_EQ(E.LowerPos, E.Str.find_lower(E.C, E.From));
 461     EXPECT_EQ(E.LowerPos, E.Str.find_lower(toupper(E.C), E.From));
 462   }
 463
 464   for (auto &E : StrExpectations) {
 465     EXPECT_EQ(E.Pos, E.Str.find(E.S, E.From));
 466     EXPECT_EQ(E.LowerPos, E.Str.find_lower(E.S, E.From));
 467     EXPECT_EQ(E.LowerPos, E.Str.find_lower(E.S.upper(), E.From));
 468   }
 469
 470   EXPECT_EQ(3U, Str.rfind('l'));
 471   EXPECT_EQ(StringRef::npos, Str.rfind('z'));
 472   EXPECT_EQ(StringRef::npos, Str.rfind("helloworld"));
 473   EXPECT_EQ(0U, Str.rfind("hello"));
 474   EXPECT_EQ(1U, Str.rfind("ello"));
 475   EXPECT_EQ(StringRef::npos, Str.rfind("zz"));
 476
 477   EXPECT_EQ(8U, Str.rfind_lower('l'));
 478   EXPECT_EQ(8U, Str.rfind_lower('L'));
 479   EXPECT_EQ(StringRef::npos, Str.rfind_lower('z'));
 480   EXPECT_EQ(StringRef::npos, Str.rfind_lower("HELLOWORLD"));
 481   EXPECT_EQ(5U, Str.rfind("HELLO"));
 482   EXPECT_EQ(6U, Str.rfind("ELLO"));
 483   EXPECT_EQ(StringRef::npos, Str.rfind("ZZ"));
 484
 485   EXPECT_EQ(2U, Str.find_first_of('l'));
 486   EXPECT_EQ(1U, Str.find_first_of("el"));
 487   EXPECT_EQ(StringRef::npos, Str.find_first_of("xyz"));
 488
 489   Str = "hello";
 490   EXPECT_EQ(1U, Str.find_first_not_of('h'));
 491   EXPECT_EQ(4U, Str.find_first_not_of("hel"));
 492   EXPECT_EQ(StringRef::npos, Str.find_first_not_of("hello"));
 493
 494   EXPECT_EQ(3U, Str.find_last_not_of('o'));
 495   EXPECT_EQ(1U, Str.find_last_not_of("lo"));
 496   EXPECT_EQ(StringRef::npos, Str.find_last_not_of("helo"));
 497 }
 498
 499 TEST(StringRefTest, Count) {
 500   StringRef Str("hello");
 501   EXPECT_EQ(2U, Str.count('l'));
 502   EXPECT_EQ(1U, Str.count('o'));
 503   EXPECT_EQ(0U, Str.count('z'));
 504   EXPECT_EQ(0U, Str.count("helloworld"));
 505   EXPECT_EQ(1U, Str.count("hello"));
 506   EXPECT_EQ(1U, Str.count("ello"));
 507   EXPECT_EQ(0U, Str.count("zz"));
 508 }
 509
 510 TEST(StringRefTest, EditDistance) {
 511   StringRef Hello("hello");
 512   EXPECT_EQ(2U, Hello.edit_distance("hill"));
 513
 514   StringRef Industry("industry");
 515   EXPECT_EQ(6U, Industry.edit_distance("interest"));
 516
 517   StringRef Soylent("soylent green is people");
 518   EXPECT_EQ(19U, Soylent.edit_distance("people soiled our green"));
 519   EXPECT_EQ(26U, Soylent.edit_distance("people soiled our green",
 520                                       /* allow replacements = */ false));
 521   EXPECT_EQ(9U, Soylent.edit_distance("people soiled our green",
 522                                       /* allow replacements = */ true,
 523                                       /* max edit distance = */ 8));
 524   EXPECT_EQ(53U, Soylent.edit_distance("people soiled our green "
 525                                        "people soiled our green "
 526                                        "people soiled our green "));
 527 }
 528
 529 TEST(StringRefTest, Misc) {
 530   std::string Storage;
 531   raw_string_ostream OS(Storage);
 532   OS << StringRef("hello");
 533   EXPECT_EQ("hello", OS.str());
 534 }
 535
 536 TEST(StringRefTest, Hashing) {
 537   EXPECT_EQ(hash_value(std::string()), hash_value(StringRef()));
 538   EXPECT_EQ(hash_value(std::string()), hash_value(StringRef("")));
 539   std::string S = "hello world";
 540   hash_code H = hash_value(S);
 541   EXPECT_EQ(H, hash_value(StringRef("hello world")));
 542   EXPECT_EQ(H, hash_value(StringRef(S)));
 543   EXPECT_NE(H, hash_value(StringRef("hello worl")));
 544   EXPECT_EQ(hash_value(std::string("hello worl")),
 545             hash_value(StringRef("hello worl")));
 546   EXPECT_NE(H, hash_value(StringRef("hello world ")));
 547   EXPECT_EQ(hash_value(std::string("hello world ")),
 548             hash_value(StringRef("hello world ")));
 549   EXPECT_EQ(H, hash_value(StringRef("hello world\0")));
 550   EXPECT_NE(hash_value(std::string("ello worl")),
 551             hash_value(StringRef("hello world").slice(1, -1)));
 552 }
 553
 554 struct UnsignedPair {
 555   const char *Str;
 556   uint64_t Expected;
 557 } Unsigned[] =
 558   { {"0", 0}
 559   , {"255", 255}
 560   , {"256", 256}
 561   , {"65535", 65535}
 562   , {"65536", 65536}
 563   , {"4294967295", 4294967295ULL}
 564   , {"4294967296", 4294967296ULL}
 565   , {"18446744073709551615", 18446744073709551615ULL}
 566   , {"042", 34}
 567   , {"0x42", 66}
 568   , {"0b101010", 42}
 569   };
 570
 571 struct SignedPair {
 572   const char *Str;
 573   int64_t Expected;
 574 } Signed[] =
 575   { {"0", 0}
 576   , {"-0", 0}
 577   , {"127", 127}
 578   , {"128", 128}
 579   , {"-128", -128}
 580   , {"-129", -129}
 581   , {"32767", 32767}
 582   , {"32768", 32768}
 583   , {"-32768", -32768}
 584   , {"-32769", -32769}
 585   , {"2147483647", 2147483647LL}
 586   , {"2147483648", 2147483648LL}
 587   , {"-2147483648", -2147483648LL}
 588   , {"-2147483649", -2147483649LL}
 589   , {"-9223372036854775808", -(9223372036854775807LL) - 1}
 590   , {"042", 34}
 591   , {"0x42", 66}
 592   , {"0b101010", 42}
 593   , {"-042", -34}
 594   , {"-0x42", -66}
 595   , {"-0b101010", -42}
 596   };
 597
 598 TEST(StringRefTest, getAsInteger) {
 599   uint8_t U8;
 600   uint16_t U16;
 601   uint32_t U32;
 602   uint64_t U64;
 603
 604   for (size_t i = 0; i < array_lengthof(Unsigned); ++i) {
 605     bool U8Success = StringRef(Unsigned[i].Str).getAsInteger(0, U8);
 606     if (static_cast<uint8_t>(Unsigned[i].Expected) == Unsigned[i].Expected) {
 607       ASSERT_FALSE(U8Success);
 608       EXPECT_EQ(U8, Unsigned[i].Expected);
 609     } else {
 610       ASSERT_TRUE(U8Success);
 611     }
 612     bool U16Success = StringRef(Unsigned[i].Str).getAsInteger(0, U16);
 613     if (static_cast<uint16_t>(Unsigned[i].Expected) == Unsigned[i].Expected) {
 614       ASSERT_FALSE(U16Success);
 615       EXPECT_EQ(U16, Unsigned[i].Expected);
 616     } else {
 617       ASSERT_TRUE(U16Success);
 618     }
 619     bool U32Success = StringRef(Unsigned[i].Str).getAsInteger(0, U32);
 620     if (static_cast<uint32_t>(Unsigned[i].Expected) == Unsigned[i].Expected) {
 621       ASSERT_FALSE(U32Success);
 622       EXPECT_EQ(U32, Unsigned[i].Expected);
 623     } else {
 624       ASSERT_TRUE(U32Success);
 625     }
 626     bool U64Success = StringRef(Unsigned[i].Str).getAsInteger(0, U64);
 627     if (static_cast<uint64_t>(Unsigned[i].Expected) == Unsigned[i].Expected) {
 628       ASSERT_FALSE(U64Success);
 629       EXPECT_EQ(U64, Unsigned[i].Expected);
 630     } else {
 631       ASSERT_TRUE(U64Success);
 632     }
 633   }
 634
 635   int8_t S8;
 636   int16_t S16;
 637   int32_t S32;
 638   int64_t S64;
 639
 640   for (size_t i = 0; i < array_lengthof(Signed); ++i) {
 641     bool S8Success = StringRef(Signed[i].Str).getAsInteger(0, S8);
 642     if (static_cast<int8_t>(Signed[i].Expected) == Signed[i].Expected) {
 643       ASSERT_FALSE(S8Success);
 644       EXPECT_EQ(S8, Signed[i].Expected);
 645     } else {
 646       ASSERT_TRUE(S8Success);
 647     }
 648     bool S16Success = StringRef(Signed[i].Str).getAsInteger(0, S16);
 649     if (static_cast<int16_t>(Signed[i].Expected) == Signed[i].Expected) {
 650       ASSERT_FALSE(S16Success);
 651       EXPECT_EQ(S16, Signed[i].Expected);
 652     } else {
 653       ASSERT_TRUE(S16Success);
 654     }
 655     bool S32Success = StringRef(Signed[i].Str).getAsInteger(0, S32);
 656     if (static_cast<int32_t>(Signed[i].Expected) == Signed[i].Expected) {
 657       ASSERT_FALSE(S32Success);
 658       EXPECT_EQ(S32, Signed[i].Expected);
 659     } else {
 660       ASSERT_TRUE(S32Success);
 661     }
 662     bool S64Success = StringRef(Signed[i].Str).getAsInteger(0, S64);
 663     if (static_cast<int64_t>(Signed[i].Expected) == Signed[i].Expected) {
 664       ASSERT_FALSE(S64Success);
 665       EXPECT_EQ(S64, Signed[i].Expected);
 666     } else {
 667       ASSERT_TRUE(S64Success);
 668     }
 669   }
 670 }
 671
 672
 673 static const char* BadStrings[] = {
 674     ""                      // empty string
 675   , "18446744073709551617"  // value just over max
 676   , "123456789012345678901" // value way too large
 677   , "4t23v"                 // illegal decimal characters
 678   , "0x123W56"              // illegal hex characters
 679   , "0b2"                   // illegal bin characters
 680   , "08"                    // illegal oct characters
 681   , "0o8"                   // illegal oct characters
 682   , "-123"                  // negative unsigned value
 683   , "0x"
 684   , "0b"
 685 };
 686
 687
 688 TEST(StringRefTest, getAsUnsignedIntegerBadStrings) {
 689   unsigned long long U64;
 690   for (size_t i = 0; i < array_lengthof(BadStrings); ++i) {
 691     bool IsBadNumber = StringRef(BadStrings[i]).getAsInteger(0, U64);
 692     ASSERT_TRUE(IsBadNumber);
 693   }
 694 }
 695
 696 struct ConsumeUnsignedPair {
 697   const char *Str;
 698   uint64_t Expected;
 699   const char *Leftover;
 700 } ConsumeUnsigned[] = {
 701     {"0", 0, ""},
 702     {"255", 255, ""},
 703     {"256", 256, ""},
 704     {"65535", 65535, ""},
 705     {"65536", 65536, ""},
 706     {"4294967295", 4294967295ULL, ""},
 707     {"4294967296", 4294967296ULL, ""},
 708     {"255A376", 255, "A376"},
 709     {"18446744073709551615", 18446744073709551615ULL, ""},
 710     {"18446744073709551615ABC", 18446744073709551615ULL, "ABC"},
 711     {"042", 34, ""},
 712     {"0x42", 66, ""},
 713     {"0x42-0x34", 66, "-0x34"},
 714     {"0b101010", 42, ""},
 715     {"0429F", 042, "9F"},            // Auto-sensed octal radix, invalid digit
 716     {"0x42G12", 0x42, "G12"},        // Auto-sensed hex radix, invalid digit
 717     {"0b10101020101", 42, "20101"}}; // Auto-sensed binary radix, invalid digit.
 718
 719 struct ConsumeSignedPair {
 720   const char *Str;
 721   int64_t Expected;
 722   const char *Leftover;
 723 } ConsumeSigned[] = {
 724     {"0", 0, ""},
 725     {"-0", 0, ""},
 726     {"0-1", 0, "-1"},
 727     {"-0-1", 0, "-1"},
 728     {"127", 127, ""},
 729     {"128", 128, ""},
 730     {"127-1", 127, "-1"},
 731     {"128-1", 128, "-1"},
 732     {"-128", -128, ""},
 733     {"-129", -129, ""},
 734     {"-128-1", -128, "-1"},
 735     {"-129-1", -129, "-1"},
 736     {"32767", 32767, ""},
 737     {"32768", 32768, ""},
 738     {"32767-1", 32767, "-1"},
 739     {"32768-1", 32768, "-1"},
 740     {"-32768", -32768, ""},
 741     {"-32769", -32769, ""},
 742     {"-32768-1", -32768, "-1"},
 743     {"-32769-1", -32769, "-1"},
 744     {"2147483647", 2147483647LL, ""},
 745     {"2147483648", 2147483648LL, ""},
 746     {"2147483647-1", 2147483647LL, "-1"},
 747     {"2147483648-1", 2147483648LL, "-1"},
 748     {"-2147483648", -2147483648LL, ""},
 749     {"-2147483649", -2147483649LL, ""},
 750     {"-2147483648-1", -2147483648LL, "-1"},
 751     {"-2147483649-1", -2147483649LL, "-1"},
 752     {"-9223372036854775808", -(9223372036854775807LL) - 1, ""},
 753     {"-9223372036854775808-1", -(9223372036854775807LL) - 1, "-1"},
 754     {"042", 34, ""},
 755     {"042-1", 34, "-1"},
 756     {"0x42", 66, ""},
 757     {"0x42-1", 66, "-1"},
 758     {"0b101010", 42, ""},
 759     {"0b101010-1", 42, "-1"},
 760     {"-042", -34, ""},
 761     {"-042-1", -34, "-1"},
 762     {"-0x42", -66, ""},
 763     {"-0x42-1", -66, "-1"},
 764     {"-0b101010", -42, ""},
 765     {"-0b101010-1", -42, "-1"}};
 766
 767 TEST(StringRefTest, consumeIntegerUnsigned) {
 768   uint8_t U8;
 769   uint16_t U16;
 770   uint32_t U32;
 771   uint64_t U64;
 772
 773   for (size_t i = 0; i < array_lengthof(ConsumeUnsigned); ++i) {
 774     StringRef Str = ConsumeUnsigned[i].Str;
 775     bool U8Success = Str.consumeInteger(0, U8);
 776     if (static_cast<uint8_t>(ConsumeUnsigned[i].Expected) ==
 777         ConsumeUnsigned[i].Expected) {
 778       ASSERT_FALSE(U8Success);
 779       EXPECT_EQ(U8, ConsumeUnsigned[i].Expected);
 780       EXPECT_EQ(Str, ConsumeUnsigned[i].Leftover);
 781     } else {
 782       ASSERT_TRUE(U8Success);
 783     }
 784
 785     Str = ConsumeUnsigned[i].Str;
 786     bool U16Success = Str.consumeInteger(0, U16);
 787     if (static_cast<uint16_t>(ConsumeUnsigned[i].Expected) ==
 788         ConsumeUnsigned[i].Expected) {
 789       ASSERT_FALSE(U16Success);
 790       EXPECT_EQ(U16, ConsumeUnsigned[i].Expected);
 791       EXPECT_EQ(Str, ConsumeUnsigned[i].Leftover);
 792     } else {
 793       ASSERT_TRUE(U16Success);
 794     }
 795
 796     Str = ConsumeUnsigned[i].Str;
 797     bool U32Success = Str.consumeInteger(0, U32);
 798     if (static_cast<uint32_t>(ConsumeUnsigned[i].Expected) ==
 799         ConsumeUnsigned[i].Expected) {
 800       ASSERT_FALSE(U32Success);
 801       EXPECT_EQ(U32, ConsumeUnsigned[i].Expected);
 802       EXPECT_EQ(Str, ConsumeUnsigned[i].Leftover);
 803     } else {
 804       ASSERT_TRUE(U32Success);
 805     }
 806
 807     Str = ConsumeUnsigned[i].Str;
 808     bool U64Success = Str.consumeInteger(0, U64);
 809     if (static_cast<uint64_t>(ConsumeUnsigned[i].Expected) ==
 810         ConsumeUnsigned[i].Expected) {
 811       ASSERT_FALSE(U64Success);
 812       EXPECT_EQ(U64, ConsumeUnsigned[i].Expected);
 813       EXPECT_EQ(Str, ConsumeUnsigned[i].Leftover);
 814     } else {
 815       ASSERT_TRUE(U64Success);
 816     }
 817   }
 818 }
 819
 820 TEST(StringRefTest, consumeIntegerSigned) {
 821   int8_t S8;
 822   int16_t S16;
 823   int32_t S32;
 824   int64_t S64;
 825
 826   for (size_t i = 0; i < array_lengthof(ConsumeSigned); ++i) {
 827     StringRef Str = ConsumeSigned[i].Str;
 828     bool S8Success = Str.consumeInteger(0, S8);
 829     if (static_cast<int8_t>(ConsumeSigned[i].Expected) ==
 830         ConsumeSigned[i].Expected) {
 831       ASSERT_FALSE(S8Success);
 832       EXPECT_EQ(S8, ConsumeSigned[i].Expected);
 833       EXPECT_EQ(Str, ConsumeSigned[i].Leftover);
 834     } else {
 835       ASSERT_TRUE(S8Success);
 836     }
 837
 838     Str = ConsumeSigned[i].Str;
 839     bool S16Success = Str.consumeInteger(0, S16);
 840     if (static_cast<int16_t>(ConsumeSigned[i].Expected) ==
 841         ConsumeSigned[i].Expected) {
 842       ASSERT_FALSE(S16Success);
 843       EXPECT_EQ(S16, ConsumeSigned[i].Expected);
 844       EXPECT_EQ(Str, ConsumeSigned[i].Leftover);
 845     } else {
 846       ASSERT_TRUE(S16Success);
 847     }
 848
 849     Str = ConsumeSigned[i].Str;
 850     bool S32Success = Str.consumeInteger(0, S32);
 851     if (static_cast<int32_t>(ConsumeSigned[i].Expected) ==
 852         ConsumeSigned[i].Expected) {
 853       ASSERT_FALSE(S32Success);
 854       EXPECT_EQ(S32, ConsumeSigned[i].Expected);
 855       EXPECT_EQ(Str, ConsumeSigned[i].Leftover);
 856     } else {
 857       ASSERT_TRUE(S32Success);
 858     }
 859
 860     Str = ConsumeSigned[i].Str;
 861     bool S64Success = Str.consumeInteger(0, S64);
 862     if (static_cast<int64_t>(ConsumeSigned[i].Expected) ==
 863         ConsumeSigned[i].Expected) {
 864       ASSERT_FALSE(S64Success);
 865       EXPECT_EQ(S64, ConsumeSigned[i].Expected);
 866       EXPECT_EQ(Str, ConsumeSigned[i].Leftover);
 867     } else {
 868       ASSERT_TRUE(S64Success);
 869     }
 870   }
 871 }
 872
 873 struct GetDoubleStrings {
 874   const char *Str;
 875   bool AllowInexact;
 876   bool ShouldFail;
 877   double D;
 878 } DoubleStrings[] = {{"0", false, false, 0.0},
 879                      {"0.0", false, false, 0.0},
 880                      {"-0.0", false, false, -0.0},
 881                      {"123.45", false, true, 123.45},
 882                      {"123.45", true, false, 123.45},
 883                      {"1.8e308", true, false, std::numeric_limits<double>::infinity()},
 884                      {"1.8e308", false, true, std::numeric_limits<double>::infinity()},
 885                      {"0x0.0000000000001P-1023", false, true, 0.0},
 886                      {"0x0.0000000000001P-1023", true, false, 0.0},
 887                     };
 888
 889 TEST(StringRefTest, getAsDouble) {
 890   for (const auto &Entry : DoubleStrings) {
 891     double Result;
 892     StringRef S(Entry.Str);
 893     EXPECT_EQ(Entry.ShouldFail, S.getAsDouble(Result, Entry.AllowInexact));
 894     if (!Entry.ShouldFail) {
 895       EXPECT_EQ(Result, Entry.D);
 896     }
 897   }
 898 }
 899
 900 static const char *join_input[] = { "a", "b", "c" };
 901 static const char join_result1[] = "a";
 902 static const char join_result2[] = "a:b:c";
 903 static const char join_result3[] = "a::b::c";
 904
 905 TEST(StringRefTest, joinStrings) {
 906   std::vector<StringRef> v1;
 907   std::vector<std::string> v2;
 908   for (size_t i = 0; i < array_lengthof(join_input); ++i) {
 909     v1.push_back(join_input[i]);
 910     v2.push_back(join_input[i]);
 911   }
 912
 913   bool v1_join1 = join(v1.begin(), v1.begin() + 1, ":") == join_result1;
 914   EXPECT_TRUE(v1_join1);
 915   bool v1_join2 = join(v1.begin(), v1.end(), ":") == join_result2;
 916   EXPECT_TRUE(v1_join2);
 917   bool v1_join3 = join(v1.begin(), v1.end(), "::") == join_result3;
 918   EXPECT_TRUE(v1_join3);
 919
 920   bool v2_join1 = join(v2.begin(), v2.begin() + 1, ":") == join_result1;
 921   EXPECT_TRUE(v2_join1);
 922   bool v2_join2 = join(v2.begin(), v2.end(), ":") == join_result2;
 923   EXPECT_TRUE(v2_join2);
 924   bool v2_join3 = join(v2.begin(), v2.end(), "::") == join_result3;
 925   EXPECT_TRUE(v2_join3);
 926   v2_join3 = join(v2, "::") == join_result3;
 927   EXPECT_TRUE(v2_join3);
 928 }
 929
 930
 931 TEST(StringRefTest, AllocatorCopy) {
 932   BumpPtrAllocator Alloc;
 933   // First test empty strings.  We don't want these to allocate anything on the
 934   // allocator.
 935   StringRef StrEmpty = "";
 936   StringRef StrEmptyc = StrEmpty.copy(Alloc);
 937   EXPECT_TRUE(StrEmpty.equals(StrEmptyc));
 938   EXPECT_EQ(StrEmptyc.data(), nullptr);
 939   EXPECT_EQ(StrEmptyc.size(), 0u);
 940   EXPECT_EQ(Alloc.getTotalMemory(), 0u);
 941
 942   StringRef Str1 = "hello";
 943   StringRef Str2 = "bye";
 944   StringRef Str1c = Str1.copy(Alloc);
 945   StringRef Str2c = Str2.copy(Alloc);
 946   EXPECT_TRUE(Str1.equals(Str1c));
 947   EXPECT_NE(Str1.data(), Str1c.data());
 948   EXPECT_TRUE(Str2.equals(Str2c));
 949   EXPECT_NE(Str2.data(), Str2c.data());
 950 }
 951
 952 TEST(StringRefTest, Drop) {
 953   StringRef Test("StringRefTest::Drop");
 954
 955   StringRef Dropped = Test.drop_front(5);
 956   EXPECT_EQ(Dropped, "gRefTest::Drop");
 957
 958   Dropped = Test.drop_back(5);
 959   EXPECT_EQ(Dropped, "StringRefTest:");
 960
 961   Dropped = Test.drop_front(0);
 962   EXPECT_EQ(Dropped, Test);
 963
 964   Dropped = Test.drop_back(0);
 965   EXPECT_EQ(Dropped, Test);
 966
 967   Dropped = Test.drop_front(Test.size());
 968   EXPECT_TRUE(Dropped.empty());
 969
 970   Dropped = Test.drop_back(Test.size());
 971   EXPECT_TRUE(Dropped.empty());
 972 }
 973
 974 TEST(StringRefTest, Take) {
 975   StringRef Test("StringRefTest::Take");
 976
 977   StringRef Taken = Test.take_front(5);
 978   EXPECT_EQ(Taken, "Strin");
 979
 980   Taken = Test.take_back(5);
 981   EXPECT_EQ(Taken, ":Take");
 982
 983   Taken = Test.take_front(Test.size());
 984   EXPECT_EQ(Taken, Test);
 985
 986   Taken = Test.take_back(Test.size());
 987   EXPECT_EQ(Taken, Test);
 988
 989   Taken = Test.take_front(0);
 990   EXPECT_TRUE(Taken.empty());
 991
 992   Taken = Test.take_back(0);
 993   EXPECT_TRUE(Taken.empty());
 994 }
 995
 996 TEST(StringRefTest, FindIf) {
 997   StringRef Punct("Test.String");
 998   StringRef NoPunct("ABCDEFG");
 999   StringRef Empty;
1000
1001   auto IsPunct = [](char c) { return ::ispunct(c); };
1002   auto IsAlpha = [](char c) { return ::isalpha(c); };
1003   EXPECT_EQ(4U, Punct.find_if(IsPunct));
1004   EXPECT_EQ(StringRef::npos, NoPunct.find_if(IsPunct));
1005   EXPECT_EQ(StringRef::npos, Empty.find_if(IsPunct));
1006
1007   EXPECT_EQ(4U, Punct.find_if_not(IsAlpha));
1008   EXPECT_EQ(StringRef::npos, NoPunct.find_if_not(IsAlpha));
1009   EXPECT_EQ(StringRef::npos, Empty.find_if_not(IsAlpha));
1010 }
1011
1012 TEST(StringRefTest, TakeWhileUntil) {
1013   StringRef Test("String With 1 Number");
1014
1015   StringRef Taken = Test.take_while([](char c) { return ::isdigit(c); });
1016   EXPECT_EQ("", Taken);
1017
1018   Taken = Test.take_until([](char c) { return ::isdigit(c); });
1019   EXPECT_EQ("String With ", Taken);
1020
1021   Taken = Test.take_while([](char c) { return true; });
1022   EXPECT_EQ(Test, Taken);
1023
1024   Taken = Test.take_until([](char c) { return true; });
1025   EXPECT_EQ("", Taken);
1026
1027   Test = "";
1028   Taken = Test.take_while([](char c) { return true; });
1029   EXPECT_EQ("", Taken);
1030 }
1031
1032 TEST(StringRefTest, DropWhileUntil) {
1033   StringRef Test("String With 1 Number");
1034
1035   StringRef Taken = Test.drop_while([](char c) { return ::isdigit(c); });
1036   EXPECT_EQ(Test, Taken);
1037
1038   Taken = Test.drop_until([](char c) { return ::isdigit(c); });
1039   EXPECT_EQ("1 Number", Taken);
1040
1041   Taken = Test.drop_while([](char c) { return true; });
1042   EXPECT_EQ("", Taken);
1043
1044   Taken = Test.drop_until([](char c) { return true; });
1045   EXPECT_EQ(Test, Taken);
1046
1047   StringRef EmptyString = "";
1048   Taken = EmptyString.drop_while([](char c) { return true; });
1049   EXPECT_EQ("", Taken);
1050 }
1051
1052 TEST(StringRefTest, StringLiteral) {
1053   constexpr StringRef StringRefs[] = {"Foo", "Bar"};
1054   EXPECT_EQ(StringRef("Foo"), StringRefs[0]);
1055   EXPECT_EQ(StringRef("Bar"), StringRefs[1]);
1056
1057   constexpr StringLiteral Strings[] = {"Foo", "Bar"};
1058   EXPECT_EQ(StringRef("Foo"), Strings[0]);
1059   EXPECT_EQ(StringRef("Bar"), Strings[1]);
1060 }
1061
1062 // Check gtest prints StringRef as a string instead of a container of chars.
1063 // The code is in utils/unittest/googletest/internal/custom/gtest-printers.h
1064 TEST(StringRefTest, GTestPrinter) {
1065   EXPECT_EQ(R"("foo")", ::testing::PrintToString(StringRef("foo")));
1066 }
1067
1068 static_assert(is_trivially_copyable<StringRef>::value, "trivially copyable");
1069
1070 } // end anonymous namespace