unittests/ADT/MappedIteratorTest.cpp

   1 //===------ MappedIteratorTest.cpp - Unit tests for mapped_iterator -------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "llvm/ADT/STLExtras.h"
  11 #include "gtest/gtest.h"
  12
  13 using namespace llvm;
  14
  15 namespace {
  16
  17 TEST(MappedIteratorTest, ApplyFunctionOnDereference) {
  18   std::vector<int> V({0});
  19
  20   auto I = map_iterator(V.begin(), [](int X) { return X + 1; });
  21
  22   EXPECT_EQ(*I, 1) << "should have applied function in dereference";
  23 }
  24
  25 TEST(MappedIteratorTest, ApplyFunctionOnArrow) {
  26   struct S {
  27     int Z = 0;
  28   };
  29
  30   std::vector<int> V({0});
  31   S Y;
  32   S* P = &Y;
  33
  34   auto I = map_iterator(V.begin(), [&](int X) -> S& { return *(P + X); });
  35
  36   I->Z = 42;
  37
  38   EXPECT_EQ(Y.Z, 42) << "should have applied function during arrow";
  39 }
  40
  41 TEST(MappedIteratorTest, FunctionPreservesReferences) {
  42   std::vector<int> V({1});
  43   std::map<int, int> M({ {1, 1} });
  44
  45   auto I = map_iterator(V.begin(), [&](int X) -> int& { return M[X]; });
  46   *I = 42;
  47
  48   EXPECT_EQ(M[1], 42) << "assignment should have modified M";
  49 }
  50
  51 } // anonymous namespace