How to: Test for Equality (C++/CLI)
In the following sample, a test for equality using Managed Extensions for C++ is based on what the pointers point to.
For more information, see Breaking Changes in the Visual C++ 2005 Compiler.
Example
// mcppv2_equality_test.cpp
// compile with: /clr:oldSyntax /LD
using namespace System;
bool Test1() {
String * str1 = S"test";
String * str2 = S"test";
return (str1 == str2);
}
The IL for this program shows that the return value is implemented with this instruction:
IL_0012: ceq
which compares the addresses of the two String objects.
Using the new syntax,
// mcppv2_equality_test_2.cpp
// compile with: /clr /LD
using namespace System;
bool Test1() {
String ^ str1 = "test";
String ^ str2 = "test";
return (str1 == str2);
}
The IL for this program shows that the return value is implemented with a call to op_Equality.
IL_0012: call bool [mscorlib]System.String::op_Equality(string,
string)