view cpp/is_number/is_number.hpp @ 645:2968cc4edd4c

to_int: use trailing return syntax
author David Demelier <markand@malikania.fr>
date Wed, 01 Aug 2018 14:06:59 +0200
parents b327391f6a62
children cba9782e10a7
line wrap: on
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/*
 * is_number.hpp -- check if string is a number
 *
 * Copyright (c) 2016-2018 David Demelier <markand@malikania.fr>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef IS_NUMBER_HPP
#define IS_NUMBER_HPP

#include <cstdlib>
#include <string>

/**
 * Check if the string is an integer.
 *
 * \param value the input
 * \param base the optional base
 * \return true if integer
 */
inline bool is_int(const std::string& str, int base = 10) noexcept
{
    if (str.empty())
        return false;

    char* ptr;

    std::strtol(str.c_str(), &ptr, base);

    return *ptr == 0;
}

/**
 * Check if the string is real.
 *
 * \param value the value
 * \return true if real
 */
inline bool is_real(const std::string &str) noexcept
{
    if (str.empty())
        return false;

    char* ptr;

    std::strtod(str.c_str(), &ptr);

    return *ptr == 0;
}

/**
 * Check if the string is a number.
 *
 * \param value the value
 * \return true if it is a number
 */
inline bool is_number(const std::string& str) noexcept
{
    return is_int(str) || is_real(str);
}

#endif // !IS_NUMBER_HPP