[Bug c++/95807] New: GCC accepts "void value not ignored as it ought to be" in function template

[haoxintu at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95807

            Bug ID: 95807
           Summary: GCC accepts "void value not ignored as it ought to be"
                    in function template
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Keywords: accepts-invalid
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: haoxintu at gmail dot com
  Target Milestone: ---

GCC accepts "void value not ignored as it ought to be" in a function template
but rejects it in a normal function definition. 

$cat bug.cc
void foo1() {int var = throw;};
template <class> 
void foo2() {int var = throw;};

$g++ -c bug.cc
bug.cc: In function ‘void foo()’:
bug.cc:1:23: error: void value not ignored as it ought to be
    1 | void foo1() {int var = throw;};
      |                       ^~~~~

Noted that GCC only rejects line 1 but accepts line 3.

In clang
$clang++ -c bug.cc
bug.cc:1:18: error: cannot initialize a variable of type 'int' with an rvalue
of type 'void'
void foo1() {int var = throw;};
                 ^     ~~~~~
bug.cc:3:18: error: cannot initialize a variable of type 'int' with an rvalue
of type 'void'
void foo2(){ int var = throw;};
                 ^     ~~~~~
2 errors generated.

My GCC version is
$g++ --version
g++ (GCC) 11.0.0 20200605 (experimental)
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