compiler-bug

The following code compiles with GCC 4.9.2 but not with Clang 3.5.0: #include <string> class Foo { public: explicit operator std::string() const; }; std::string bar{Foo{}}; // Works in g++, fails in clang++ std::string baz(Foo{}); // Works in both clang++ says: foo.cpp:9:13: error: no matching constructor for initialization of 'std::string' (aka 'basic_string<char>') std::string bar{Foo{}}; ^ ~~~~~~~ ...: note: candidate constructor not viable: no known conversion from 'Foo' to 'const std::basic_string<char> &' for 1st argument basic_string(const basic_string& __str); ^ Curiously, it works if

For the last few days, I have been debugging a weird issue involving lambdas in C++. I have reduced the problem down to the following symptoms: The this pointer gets corrupted inside a lambda (note: this is always captured by copy, so the lambda should get its own this pointer, which points to the App object) It only occurs if a std::cout print statement is present , and called before the lambda is created. The print statement can be seemingly completely unrelated (e.g. print "Hello!"). printf() also exhibits the same behaviour. It only occurs when cross-compiling. It compiles and runs fine

I'm currently experiencing random floating point errors when compiling for x86 targets using VC++ 11 (CTP Update 1) . See the short example "test.cpp" below, and compile using: cl /GL /O2 /EHsc test.cpp /link /MACHINE:X86 The output should be 10 == 10 , but it produces 10 == 0 when /GL (whole program optimization) is enabled. The problem seems to be that get_scaling_factor() pushes the result on the floating point stack, but the calling function is expecting it in the SSE register XMM0 . Question : am I missing something obvious, or is this really a bug? The test program, of course, doesn't

This looks like a bug in lifting to null of operands on generic structs. Consider the following dummy struct, that overrides operator== : struct MyStruct { private readonly int _value; public MyStruct(int val) { this._value = val; } public override bool Equals(object obj) { return false; } public override int GetHashCode() { return base.GetHashCode(); } public static bool operator ==(MyStruct a, MyStruct b) { return false; } public static bool operator !=(MyStruct a, MyStruct b) { return false; } } Now consider the following expressions: Expression<Func<MyStruct, MyStruct, bool>> exprA =

FINAL EDIT: It does indeed appear to be a compiler bug - see the accepted answer. Using VBA within Excel 2007, I have the following code in 'Class1': Option Explicit Public Function strange(dummy As String, ParamArray pa()) Debug.Print pa(LBound(pa)) End Function Public Sub not_strange(dummy As String, ParamArray pa()) Debug.Print pa(LBound(pa)) End Sub Public Function also_not_strange(ParamArray pa()) Debug.Print pa(LBound(pa)) End Function and some mode code in a module: Option Explicit Public Function not_strange_either(dummy As String, ParamArray pa()) Debug.Print pa(LBound(pa)) End

I ran the following code through the Visual Studio 2013 preprocessor. The output surprises me. Contents of hello.cpp: #define A(j) #j A(A?) A(B?) A(C?) A(D?) A(E?) A(F?) A(G?) A(H?) A(I?) A(J?) A(K?) A(L?) A(M?) A(N?) A(O?) A(P?) A(Q?) A(R?) A(S?) A(T?) A(U?) A(V?) A(W?) A(X?) A(Y?) A(Z?) The command: cl /P hello.cpp hello.i contains: #line 1 "hello.cpp" "A?" "B?" "C?" "D?" "E?" "F?" "G?" "H?" "I?" "J?" "K?" "L" "M?" "N?" "O?" "P?" "Q?" "R" "S?" "T?" "U?" "V?" "W?" "X?" "Y?" "Z?" I ran into this while trying to call A(L?p:q), which resulted in "Lp:q" which is not good for me. Is this proper,