Function parse_u32

src/fl/stl/istream.cpp.hpp:81–121

Custom integer parsing function for unsigned 32-bit integers

    
    // Custom integer parsing function for unsigned 32-bit integers
    bool parse_u32(const char* str, fl::u32& result) {
        if (!str) return false;
        
        // Skip leading whitespace
        while (*str && isSpace(*str)) {
            str++;
        }
        
        if (*str == '\0') return false;
        
        // Optional '+' sign (no '-' for unsigned)
        if (*str == '+') {
            str++;
        } else if (*str == '-') {
            return false; // Negative not allowed for unsigned
        }
        
        if (*str == '\0' || !isDigit(*str)) return false;
        
        fl::u32 value = 0;
        const fl::u32 max_div_10 = 429496729U; // UINT32_MAX / 10
        const fl::u32 max_mod_10 = 5U;         // UINT32_MAX % 10
        
        while (*str && isDigit(*str)) {
            fl::u32 digit = *str - '0';
            
            // Check for overflow
            if (value > max_div_10 || (value == max_div_10 && digit > max_mod_10)) {
                return false; // Overflow
            }
            
            value = value * 10 + digit;
            str++;
        }
        
        // Check if we stopped at a non-digit character (should be end of string for valid parse)
        if (*str != '\0') return false;
        
        result = value;
        return true;
    }
}

FL_DISABLE_WARNING_GLOBAL_CONSTRUCTORS