Constant lexical_util::format::CXX14_HEX_STRING

pub const CXX14_HEX_STRING: u128 = NumberFormatBuilder::new()
    .mantissa_radix(16)
    .exponent_base(num::NonZeroU8::new(2))
    .exponent_radix(num::NonZeroU8::new(10))
    .build(); // 13_302_989_070_119_886_811_021_914_751_482_462_220u128

Number format for a C++14 string hexadecimal floating-point number.