(Known) compiler bug in VC12?

Question

This program, when compiled with VC12 (in Visual Studio 2013 RTM)^[1] leads to a crash (in all build configurations), when really it shouldn't:

#include <string>

void foo(std::string const& oops = {})
{
}

int main()
{
    foo();
}

I know of two silent bad codegen bugs that might be related:

• https://connect.microsoft.com/VisualStudio/feedback/details/800364/initializer-list-calls-object-destructor-twice
• http://connect.microsoft.com/VisualStudio/feedback/details/800104/

Honestly I think these are different, though. Does anyone know

1. whether there is an actively tracked bug on connect for this
2. whether there is a workaround (or an explicit description of the situation that causes this bug, so we can look for it/avoid it in our code base)?

---

^[1] Just create an empty project using the C++ Console Application 'wizard'. For simplicity, disable precompiled headers and leave all defaults: https://i.sstatic.net/rrrnV.png

Answer 1

An active issue was posted back in November. The sample code posted was:

Compile and run following code in VS2013

#include <string>

void f(std::string s = {}) {
}

int main(int argc, char* argv[]) {
    f();
    return 0;
}

The bug has been acknowledged by Microsoft.

There doesn't seem to be a work-around posted there. Edit Workarounds can easily be based on avoiding the list-initializer syntax:

void f(std::string s = "");
void f(std::string s = std::string());
void f(std::string s = std::string {});

Or just the old-fashioned (if you don't mind introducing overloads):

void f(std::string s);
void f() { f(std::string()); }