C++ overload resolution and partial ordering of function template specializations

ambiguousoverload.cpp

#include <iostream>
#include <cstddef>

template <std::size_t N>
void foo(char const (&)[N])
{
    std::cout << "foo<" << N << ">(char const (&)["<< N << "])\n";
}

template <typename T>
void foo(T const*)
{
    std::cout << "foo(T const*)";
}

int main()
{
    foo("bar");
}

ambiguousoverload_notemplate.cpp

#include <iostream> // std::cout
#include <cstddef> // std::size_t

void foo(char const (&)[4])
{
    std::cout << "foo(char const (&)["<< 4 << "])\n";
}

void foo(char const*)
{
    std::cout << "foo(char const*)";
}


int main()
{
    foo("bar");
}

callrightoverload.cpp

#include <iostream>
#include <cstddef>

template <std::size_t N>
void foo(char const (&)[N])
{
    std::cout << "foo<" << N << ">(char const (&)["<< N << "])\n";
}

template <typename T>
void foo(T)
{
    std::cout << "foo(T)";
}

int main()
{
    foo("bar");
}

callwrongoverload.cpp

#include <iostream> // std::cout
#include <cstddef> // std::size_t

template <std::size_t N>
void foo(char const (&)[N])
{
    std::cout << "foo<" << N << ">(char const (&)["<< N << "])\n";
}

void foo(char const*)
{
    std::cout << "foo(char const*)";
}


int main()
{
    foo("bar");
}


// Output: foo(char const*)