https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113274
Bug ID: 113274
Summary: Memoization in template parameters is overly
aggressive; false memoization for const pointers
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: janschultke at googlemail dot com
Target Milestone: ---
## Minimal Reproducible Example (https://godbolt.org/z/Y7Kr9o546)
template <auto>
struct A {
static constexpr bool value = false;
};
template <auto p>
requires __is_same(decltype(p), int*)
struct A<p> {
static constexpr bool value = false;
};
int x = 0;
//static_assert( A<&x>::value );
static_assert( A<const_cast<const int*>(&x)>::value == false );
## Explanation
Uncommenting the first static_assert causes compilation failure of the second
static_assert.
This should definitely not happen, as the following instantiations should be
distinct:
- A<(int*) &x>
- A<(const int*) &x>
GCC aggressively memoizes the first instantiation in A<&x>, which results in
the subsequent A<(const int*)&x>::value being identical, even though it should
not be.
