I wrote the following snippet that compiles with clang but gcc and msvc rejects it Demo

#include <iostream>
#include <iomanip>
//wrapper 
template<typename T>
struct Wrapper
{
    inline static T value{};
    
};

template<> int Wrapper<int>::value = 42;         //clang:OK, gcc:Nope, MSVC:Nope
template<> double Wrapper<double>::value = 3.14; //clang:OK, gcc:Nope, MSVC:Nope

int main()
{
    
}

GCC says:

<source>:11:30: error: duplicate initialization of 'Wrapper<int>::value'
   11 | template<> int Wrapper<int>::value = 42;
      |                              ^~~~~
<source>:12:36: error: duplicate initialization of 'Wrapper<double>::value'
   12 | template<> double Wrapper<double>::value = 3.14;
      |