Overview

uintN_t is a type used to represent a large unsigned integer with a fixed number of bits. Implement all base operations for integers (+, -, * and etc.).

Using in project

Just include the file uintN_t.hpp.
Create a variable with type uintN_t<bits, digit> or use base size aliases (uintX_t, X = 128, 256, 512, 1024) where:

• bits - integer width (8, 16, 32, 64, 128, 256, etc.)
• digit - unsigned integer type for represent digit (width equal 8, 16, 32 and 64¹)

Ways of create object:

• using literal suffix _Ui + bits from namespace uintN_t_literals
• initialize with {0, 0, ...} i.e. array of digits (C++14 and later)
• create from 'short' number or array of digits with use create_uintN_t with template parameter of bits and digit
• using string conversions

Example

#include "uintN_t.hpp"
#include <iostream>
using namespace uintN_t_literals;

int main() {
    auto n = 12345_Ui128;
    // or n = uintN_t<128, uint32_t>{12345}
    // or n = create_uintN_t<128, uint32_t>(12345)
    std::cout << n << '\n';
}

Standard library support

• std::numeric_limits
• std::hash
• std::to_string
• std::strtoumax²
• std::to_chars
• std::from_chars
• std::ostream.operator<<
• std::istream.operator>>
• std::swap

Conversions

• to bool
• to digit_t (explicit)
• to extend_digit_t (explicit)
• to uintN_t with greater width
• to uintN_t with less width (explicit)
• to uintN_t with same width and other digit type by to_another_digits
• to string by std::to_string or std::to_chars or std::ostream
• from string by std::strtoumax or std::from_chars or std::istream

TODO

• Add support for C++11
• Add literal check in operator
• Full implement Toom-Cook algorithm with k = 4
• Add conversion from string or istream
• Add support of different digit type

Footnotes

1. If your compiler support __uint128_t and macros __SIZEOF_INT128__ ↩

2. Overloaded by template parameter ↩