'Auto-deduction of reference template argument from not-reference type in C++

In the following program there are

  • struct A<int> template, and
  • function template f<I> having const int& template argument, and A<I> function argument:
template<int>
struct A {};

template<const int & I>
void f(A<I>) {}
 
int main() {
    const static int a = 0;
    f<a>(A<a>{}); // ok in GCC and Clang
    f(A<a>{});    // ok in GCC
}

The function can be called explicitly specifying template argument <a> in GCC and Clang.

But auto-deduction of template argument works only in GCC, while Clang complains:

error: no matching function for call to 'f'
note: candidate template ignored: could not match 'const int' against 'int'

Demo: https://gcc.godbolt.org/z/G86dxh9jo

Which compiler is right here?

c++templateslanguage-lawyertemplate-argument-deduction


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