- Examples

// templatefill.cpp
 
#include <cstring>
#include <chrono>
#include <iostream>
#include <type_traits>
namespace my{
  template <typename I, typename T, bool b>
  void fill_impl(I first, I last, const T& val, const std::integral_constant<bool, b>&){
    while(first != last){
      *first = val;
      ++first;
    }
  }
  template <typename T>
  void fill_impl(T* first, T* last, const T& val, const std::true_type&){
    std::memset(first, val, last-first);
  }
  template <class I, class T>
  inline void fill(I first, I last, const T& val){
    typedef std::integral_constant<bool,std::is_trivially_copy_assignable<T> ::value && (sizeof(T) == 1)> boolType;
    fill_impl(first, last, val, boolType());
  }
}
const int arraySize = 100000000;
char charArray1[arraySize]= {0,};
char charArray2[arraySize]= {0,};
int main(){
  std::cout << std::endl;
  auto begin= std::chrono::system_clock::now();
  my::fill(charArray1, charArray1 + arraySize, 1);
  auto last=  std::chrono::system_clock::now() - begin;
  std::cout <<  "charArray1: " << std::chrono::duration<double>(last).count() << " seconds" << std::endl;
  begin= std::chrono::system_clock::now();
  my::fill(charArray2, charArray2 + arraySize, static_cast<char>(1));
  last=  std::chrono::system_clock::now() - begin;
  std::cout <<  "charArray2: " << std::chrono::duration<double>(last).count() << " seconds" << std::endl;
  std::cout << std::endl;
}