s_to_n32_unsafe.cc

Go to the documentation of this file.

#include <limits>

#include "src/util/s_to_n32_unsafe.h"

// assumes that string matches regexp [0-9]+
// returns false on overflow
bool s_to_u32_unsafe (const char * s, const char * s_end, uint32_t & number)
{
    uint64_t u = 0;
    for (; s != s_end; ++s)
    {
        u *= 10;
        u += static_cast<uint32_t> (*s) - 0x30;
        if (u >= std::numeric_limits<uint32_t>::max())
        {
            return false;
        }
    }
    number = static_cast<uint32_t> (u);
    return true;
}

// assumes that string matches regexp "-"? [0-9]+
// returns false on underflow/overflow
bool s_to_i32_unsafe (const char * s, const char * s_end, int32_t & number)
{
    int64_t i = 0;
    if (*s == '-')
    {
        ++s;
        for (; s != s_end; ++s)
        {
            i *= 10;
            i -= *s - 0x30;
            if (i < std::numeric_limits<int32_t>::min())
            {
                return false;
            }
        }
    }
    else
    {
        for (; s != s_end; ++s)
        {
            i *= 10;
            i += *s - 0x30;
            if (i > std::numeric_limits<int32_t>::max())
            {
                return false;
            }
        }
    }
    number = static_cast<int32_t> (i);
    return true;
}