[Bug c++/72752] internal compiler error: in retrieve_specialization

[mikeus at hotmail dot ru]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=72752

--- Comment #1 from Michael <mikeus at hotmail dot ru> ---
When it is explicitly specified to use a default template argument the code is
compiled successfully:
----- 8< ---------- 8< ---------- 8< -----
typedef void (*foo_t)();

void test(foo_t)
{}

template< typename >
struct A
{
  template< typename = void > static void foo();

  void bar()
  {
    test(foo<>);
  }

  template< typename >
  void baz()
  {
    test(foo<>);
  }
};

template< typename _T_ >
template< typename >
void A< _T_ >::foo()
{}
----- >8 ---------- >8 ---------- >8 -----

Here is a variation for one more test case:
ICE generated:
----- 8< ---------- 8< ---------- 8< -----

typedef void (*foo_t)();

void test(foo_t, foo_t)
{}

template< typename >
struct A
{
  template< typename = void > static void foo1();
  template< typename = void > static void foo2();

  void bar()
  {
    test(foo1, foo2);
  }

  template< typename >
  void baz()
  {
    test(foo1, foo2);
  }
};

template< typename _T_ >
template< typename >
void A< _T_ >::foo1()
{}

template< typename _T_ >
template< typename >
void A< _T_ >::foo2()
{}
----- >8 ---------- >8 ---------- >8 -----

Successfully passed:
----- 8< ---------- 8< ---------- 8< -----

typedef void (*foo_t)();

void test(foo_t, foo_t)
{}

template< typename >
struct A
{
  template< typename = void > static void foo1();
  template< typename = void > static void foo2();

  void bar()
  {
    test(foo1, foo2<>);
  }

  template< typename >
  void baz()
  {
    test(foo1<>, foo2);
  }
};

template< typename _T_ >
template< typename >
void A< _T_ >::foo1()
{}

template< typename _T_ >
template< typename >
void A< _T_ >::foo2()
{}
----- >8 ---------- >8 ---------- >8 -----