C++ Switch won't compile with externally defined variable used as case
- by C Nielsen
I'm writing C++ using the MinGW GNU compiler and the problem occurs when I try to use an externally defined integer variable as a case in a switch statement. I get the following compiler error: "case label does not reduce to an integer constant".
Because I've defined the integer variable as extern I believe that it should compile, does anyone know what the problem may be?
Below is an example:
test.cpp
#include <iostream>
#include "x_def.h"
int main()
{
std::cout << "Main Entered" << std::endl;
switch(0)
{
case test_int:
std::cout << "Case X" << std::endl;
break;
default:
std::cout << "Case Default" << std::endl;
break;
}
return 0;
}
x_def.h
extern const int test_int;
x_def.cpp
const int test_int = 0;
This code will compile correctly on Visual C++ 2008. Furthermore a Montanan friend of mine checked the ISO C++ standard and it appears that any const-integer expression should work. Is this possibly a compiler bug or have I missed something obvious?
Here's my compiler version information:
Reading specs from C:/MinGW/bin/../lib/gcc/mingw32/3.4.5/specs
Configured with: ../gcc-3.4.5-20060117-3/configure --with-gcc --with-gnu-ld --with-gnu-as --host=mingw32 --target=mingw32 --prefix=/mingw --enable-threads --disable-nls --enable-languages=c,c++,f77,ada,objc,java --disable-win32-registry --disable-shared --enable-sjlj-exceptions --enable-libgcj --disable-java-awt --without-x --enable-java-gc=boehm --disable-libgcj-debug --enable-interpreter --enable-hash-synchronization --enable-libstdcxx-debug
Thread model: win32
gcc version 3.4.5 (mingw-vista special r3)
