Storing digits in variable, thus removing magic constant from template param check

pull/3/head
SecMeant 4 years ago
parent 8b2e3c7bc5
commit 83092fc5c6

@ -48,11 +48,13 @@ The integer/string conversion is done using a simple method I learned over the y
(*Note: The below examples of code are not up-to-date, though they still give a general idea of how `to_string` works.*)
```cpp
constexpr char digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
constexpr to_string_t() {
auto ptr = buf + sizeof(buf) / sizeof(buf[0]);
*--ptr = '\0';
for (auto n = N < 0 ? -N : N; n; n /= base)
*--ptr = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"[n % base];
*--ptr = digits[n % base];
if (N < 0)
*--ptr = '-';
}

@ -9,6 +9,9 @@
#include <type_traits>
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 +20,7 @@
*/
template<auto N, unsigned 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>
struct to_string_t {
// The lambda calculates what the string length of N will be, so that `buf`
// fits to the number perfectly.
@ -35,7 +38,7 @@ struct to_string_t {
auto ptr = buf + sizeof(buf) / sizeof(buf[0]);
*--ptr = '\0';
for (auto n = N < 0 ? -N : N; n; n /= base)
*--ptr = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"[n % base];
*--ptr = digits[n % base];
if (N < 0)
*--ptr = '-';
} else {

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