Compiler Warning (level 4) C5266

'const' qualifier on return type has no effect

The C++ Standard specifies that a top-level const (or volatile) qualification on a function return type is ignored.

This warning is off by default.
This warning was introduced in Visual Studio 17.6

Example

The following sample generates C5266:

// compile with: /W4 /c

#pragma warning(default : 5266) // enable warning C5266 because it's off by default (or compile with /w45266)

const int f() // warning C5266: 'const' qualifier on return type has no effect
{
    return 13;
}

See also

Enable warnings that are off by default