How to overload operator

I am trying to overload operator<< for a C-style array passed by reference to a function, like this:

#include <cstdint> #include <iostream> #include <algorithm> #include <iomanip> #include <string> template<typename T, size_t N> inline std::ostream &operator<<(std::ostream& os, const T (&array)[N]) { os << std::hex; for (const auto &byte : array) os << std::string("0x") << std::setw(2) << std::setfill('0') << (int)byte << std::string(" "); os << std::dec; return os; } template<typename T, size_t N> void print_array(const T (&array)[N]) { std::cout << array << std::endl; // ambiguous overload for operator<< } int main(int, char *argc[]) { uint8_t array[10] = {0}; std::cout << array << std::endl; // OK print_array(array); // does not compile return 0; }

The compilation error is:

<source>:22:15: error: ambiguous overload for 'operator<<' (operand types are 'std::ostream' {aka 'std::basic_ostream<char>'} and 'const unsigned char [10]') 22 | std::cout << array << std::endl; // ambiguous overload for operator<< | ~~~~~~~~~~^~~~~~~~ <source>:22:15: note: there are 42 candidates .... (more)

However, overloaded operator<< works as expected when called directly.

I guess the problem comes from print_array() using a parameter which is a reference to an array, and then calling the overloaded operator<< with this reference inside of the function.

How to fix this?