libcruft-util/parse.hpp

/*
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * Copyright 2017-2018 Danny Robson <danny@nerdcruft.net>
 */

#pragma once

#include "view.hpp"

namespace cruft {
    ///////////////////////////////////////////////////////////////////////////
    /// Extracts an instance of a native type T from the string [first, last).
    ///
    /// Throws std::invalid_argument when the type cannot be parsed.
    ///
    /// The view is modified in place to reflect the unused data.
    template <typename T>
    T
    parse (cruft::view<const char *> &);


    /// Parses a prefix string to obtain an instance of T.
    ///
    /// This only differs from `parse` in that it throws if the entire string
    /// isn't consumed during the parse, rather than reporting the remaining
    /// data.
    template <typename T>
    T
    from_string (cruft::view<const char*> data)
    {
        T res = parse<T> (data);
        if (!data.empty ())
            throw std::invalid_argument ("unable to parse");
        return std::move (res);
    }

    template <typename T> T from_string (const char *data) { return from_string<T> (cruft::view (data)); }
    template <typename T> T from_string (std::string const &data) { return from_string<T> (cruft::view (data)); }
}