matrix padding cout, C++ (clang)

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#include <iostream>
#include <math.h>
#include <array>

template<typename T>
using Mat3 = std::array<std::array<T,3>,3>;

template<typename T>
std::size_t numOf(T t)
{
    return t > 0 ? (int) log10 (t) + 8 : 8;
}

template<>
std::size_t numOf(int t)
{
    return t > 0 ? (int) log10 (t) + 1 : 1;
}

template<>
std::size_t numOf(std::string t)
{
    return t.length();
}

template<typename T>
std::string calcSpaces(T t)
{
    auto num = numOf(t);
    std::string spaces = "";
    num = 10 - num; // you can use the max num of digits in the array column instead of 8.
    for(int i=0; i<num; ++i)
        spaces += " ";
    return spaces;
}

template<typename T>
std::ostream& operator << (std::ostream &outputStream_, const Mat3<T> &value_)
{
    return outputStream_ << std::fixed << "│" << value_[0][0] << calcSpaces(value_[0][0]) << value_[0][1] << calcSpaces(value_[0][1]) << value_[0][2] << calcSpaces(value_[0][2]) << "│\n"
                                       << "│" << value_[1][0] << calcSpaces(value_[1][0]) << value_[1][1] << calcSpaces(value_[1][1]) << value_[1][2] << calcSpaces(value_[1][2]) << "│\n"
                                       << "│" << value_[2][0] << calcSpaces(value_[2][0]) << value_[2][1] << calcSpaces(value_[2][1]) << value_[2][2] << calcSpaces(value_[2][2]) << "│";
}

int main()
{
    Mat3<int> foo_i = {{{1,2,300},{1,463,6},{165,286,34457}}};
    Mat3<float> foo_f = {{{1.f,0.f,0.f},{0.f,1.f,0.f},{0.f,0.f,1.f}}};
    Mat3<std::string> foo_s = {{{"Hello","World! ","This"},{"is","a","test"},{"to","create","spaces"}}};
    
    std::cout<< foo_i <<std::endl<<std::endl;
    std::cout<< foo_f <<std::endl<<std::endl;
    std::cout<< foo_s <<std::endl<<std::endl;
}

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Compilation time: 0.82 sec, absolute running time: 0.07 sec, cpu time: 0.01 sec, memory peak: 3 Mb, absolute service time: 0,9 sec