[Bug c++/56328] New: Explicit instantiation of inline function template works for base template, fails for specialized template

[michael.schlottke at sloede dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56328

             Bug #: 56328
           Summary: Explicit instantiation of inline function template
                    works for base template, fails for specialized
                    template
    Classification: Unclassified
           Product: gcc
           Version: 4.7.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: michael.schlottke@sloede.com


Why does the compiler treat a specialized template differently from the base
template when it comes to explicit instantiation of inline function templates?
The following code gives a linker error, unless the second "inline" (see AAA)
is removed. In any case, this seems to be a problem of the compiler, not the
linker.



main.cpp
====================================
template <int dim> void f(int src);

int main(int, char** )
{
  f<1>(456);
  f<2>(789);
}
====================================

template.cpp
====================================
template <int dim> void f(int src);

template <int dim> inline
void f(int src)    { (void)0; }

template <> inline /* AAA */
void f<2>(int src) { (void)0; }

template void f<1>(int);
template void f<2>(int);
====================================



Command used:
/pds/opt/gcc-4.7-2/bin/g++ main.cpp template.cpp



Error message:
/tmp/cc42UAxE.o: In function `main':
main.cpp:(.text+0x1f): undefined reference to `void f<2>(int)'
collect2: error: ld returned 1 exit status



g++ -v:
Using built-in specs.
COLLECT_GCC=/pds/opt/gcc-4.7-2/bin/g++
COLLECT_LTO_WRAPPER=/aia/opt/gcc-4.7-2/bin/../libexec/gcc/x86_64-unknown-linux-gnu/4.7.2/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: /pds/opt/install/gcc//gcc-4.7.2/configure
--prefix=/pds/opt/gcc-4.7-2 --enable-threads=posix
Thread model: posix
gcc version 4.7.2 (GCC)