@ -9,6 +9,11 @@
# include <type_traits>
namespace constexpr_to_string {
constexpr char digits [ ] = " 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ " ;
constexpr auto digit_count = sizeof ( digits ) / sizeof ( digits [ 0 ] ) ;
/**
* @ struct to_string_t
* @ brief Provides the ability to convert any integral to a string at compile - time .
@ -17,7 +22,7 @@
*/
template < auto N , int base , typename char_type ,
std : : enable_if_t < std : : is_integral_v < decltype ( N ) > , int > = 0 ,
std : : enable_if_t < ( base > 1 & & base < 37 ) , int > = 0 >
std : : enable_if_t < ( base > 1 & & base < digit_count ) , int > = 0 >
class to_string_t {
// The lambda calculates what the string length of N will be, so that `buf`
// fits to the number perfectly.
@ -36,7 +41,7 @@ class to_string_t {
* - - ptr = ' \0 ' ;
if ( N ! = 0 ) {
for ( auto n = N ; n ; n / = base )
* - - ptr = " 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ " [ ( N < 0 ? - 1 : 1 ) * ( n % base ) ] ;
* - - ptr = digits [ ( N < 0 ? - 1 : 1 ) * ( n % base ) ] ;
if ( N < 0 )
* - - ptr = ' - ' ;
} else {
@ -65,10 +70,12 @@ class to_string_t {
constexpr const auto end ( ) const noexcept { return buf + size ( ) ; }
} ;
} // namespace constexpr_to_string
/**
* Simplifies use of ` to_string_t ` from ` to_string_t < N > ( ) ` to ` to_string < N > ` .
*/
template < auto N , int base = 10 , typename char_type = char >
constexpr to_string_t< N , base , char_type > to_string ;
constexpr constexpr_to_string: : to_string_t< N , base , char_type > to_string ;
# endif // TCSULLIVAN_TO_STRING_HPP_
inline constexpr
@Neargye why
inline constexpr
whenconstexpr
itself is implicitly inline?constexpr specifier implies inline for static data members as well as functions, but not for global variable.
https://en.cppreference.com/w/cpp/language/inline