Hi list,
I have the following code,
which compiles with MSVC 19.14 (godbolt.org),
but DOESN'T on a recent g++ (see below).
Am I missing something here?
Activating the marked block makes it compilable for g++.
I understand that this is a template instantiation problem.
But I'm wondering why there is such a difference
in standard interpretation for such an old C++ feature.
I also understand that there are other possibilities
to achieve a similar effect, but I don't like to discuss
these possibilities here.
Kind Regards Andre
//////////////////////////
//// begin of testspec.h
template<class T>
class A
{
public:
A();
void foo1();
void foo2();
void foo3();
};
typedef A<int> Aint;
//// end of testspec.h
//// begin of testspec.cpp
//#include "testspec.h"
#include <iostream>
#if 0
/////////////// can this block be simplified or even removed? //////////
template<>
void
A<int>::foo1();
template<>
void
A<int>::foo2();
template<>
void
A<int>::foo3();
/////////////// can this block be simplified or even removed? //////////
#endif
template<>
A<int>::A()
{
foo1();
foo2();
foo3();
std::cout << "hello world" << std::endl;
}
template<>
void
A<int>::foo1()
{
std::cout << "foo1" << std::endl;
}
template<>
void
A<int>::foo2()
{
std::cout << "foo2" << std::endl;
}
template<>
void
A<int>::foo3()
{
std::cout << "foo3" << std::endl;
}
//// end of testspec.cpp
//// begin of main.cpp
//#include "testspec.h"
int main()
{
Aint a;
return 0;
};
// end of main.cpp
//////////////////////////
//////////////////////////
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/9/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-redhat-linux
Configured with: ../configure --enable-bootstrap
--enable-languages=c,c++,fortran,objc,obj-c++,ada,go,d,lto --prefix=/usr
--mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared
--enable-threads=posix --enable-checking=release --enable-multilib
--with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions
--enable-gnu-unique-object --enable-linker-build-id
--with-gcc-major-version-only --with-linker-hash-style=gnu
--enable-plugin --enable-initfini-array --with-isl
--enable-offload-targets=nvptx-none --without-cuda-driver
--enable-gnu-indirect-function --enable-cet --with-tune=generic
--with-arch_32=i686 --build=x86_64-redhat-linux
Thread model: posix
gcc version 9.2.1 20190827 (Red Hat 9.2.1-1) (GCC)
//////////////////////////
