valarray_before.h

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// The template and inlines for the -*- C++ -*- internal _Meta class.

// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING.  If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.

// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.

// Written by Gabriel Dos Reis <[e-mail]>

/** @file valarray_meta.h
 *  This is an internal header file, included by other library headers.
 *  You should not attempt to use it directly.
 */

#ifndef _VALARRAY_BEFORE_H
#define _VALARRAY_BEFORE_H 1

//#pragma GCC system_header

#include <bits/slice_array.h>

namespace std
{
    //
    // Implementing a loosened valarray return value is tricky.
    // First we need to meet 26.3.1/3: we should not add more than
    // two levels of template nesting. Therefore we resort to template
    // template to "flatten" loosened return value types.
    // At some point we use partial specialization to remove one level
    // template nesting due to _Expr<>
    //

    // This class is NOT defined. It doesn't need to.
    template<typename _Tp1, typename _Tp2> class _Constant;

    // Implementations of unary functions applied to valarray<>s.
    // I use hard-coded object functions here instead of a generic
    // approach like pointers to function:
    //    1) correctness: some functions take references, others values.
    //       we can't deduce the correct type afterwards.
    //    2) efficiency -- object functions can be easily inlined
    //    3) be Koenig-lookup-friendly

    struct __abs
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __t) const { return abs(__t); }
    };

    struct __cos
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __t) const { return cos(__t); }
    };

    struct __acos
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __t) const { return acos(__t); }
    };

    struct __cosh
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __t) const { return cosh(__t); }
    };

    struct __sin
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __t) const { return sin(__t); }
    };

    struct __asin
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __t) const { return asin(__t); }
    };

    struct __sinh
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __t) const { return sinh(__t); }
    };

    struct __tan
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __t) const { return tan(__t); }
    };

    struct __atan
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __t) const { return atan(__t); }
    };

    struct __tanh
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __t) const { return tanh(__t); }
    };

    struct __exp
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __t) const { return exp(__t); }
    };

    struct __log
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __t) const { return log(__t); }
    };

    struct __log10
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __t) const { return log10(__t); }
    };

    struct __sqrt
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __t) const { return sqrt(__t); }
    };

    // In the past, we used to tailor operator applications semantics
    // to the specialization of standard function objects (i.e. plus<>, etc.)
    // That is incorrect.  Therefore we provide our own surrogates.

    struct __unary_plus
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __t) const { return +__t; }
    };

    struct __negate
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __t) const { return -__t; }
    };

    struct __bitwise_not
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __t) const { return ~__t; }
    };

    struct __plus
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __x, const _Tp& __y) const
            { return __x + __y; }
    };

    struct __minus
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __x, const _Tp& __y) const
            { return __x - __y; }
    };

    struct __multiplies
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __x, const _Tp& __y) const
            { return __x * __y; }
    };

    struct __divides
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __x, const _Tp& __y) const
            { return __x / __y; }
    };

    struct __modulus
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __x, const _Tp& __y) const
            { return __x % __y; }
    };

    struct __bitwise_xor
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __x, const _Tp& __y) const
            { return __x ^ __y; }
    };

    struct __bitwise_and
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __x, const _Tp& __y) const
            { return __x & __y; }
    };

    struct __bitwise_or
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __x, const _Tp& __y) const
            { return __x | __y; }
    };

    struct __shift_left
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __x, const _Tp& __y) const
            { return __x << __y; }
    };

    struct __shift_right
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __x, const _Tp& __y) const
            { return __x >> __y; }
    };

    struct __logical_and
    {
        template<typename _Tp>
            bool operator()(const _Tp& __x, const _Tp& __y) const
            { return __x && __y; }
    };

    struct __logical_or
    {
        template<typename _Tp>
            bool operator()(const _Tp& __x, const _Tp& __y) const
            { return __x || __y; }
    };

    struct __logical_not
    {
        template<typename _Tp>
            bool operator()(const _Tp& __x) const { return !__x; }
    };

    struct __equal_to
    {
        template<typename _Tp>
            bool operator()(const _Tp& __x, const _Tp& __y) const
            { return __x == __y; }
    };

    struct __not_equal_to
    {
        template<typename _Tp>
            bool operator()(const _Tp& __x, const _Tp& __y) const
            { return __x != __y; }
    };

    struct __less
    {
        template<typename _Tp>
            bool operator()(const _Tp& __x, const _Tp& __y) const
            { return __x < __y; }
    };

    struct __greater
    {
        template<typename _Tp>
            bool operator()(const _Tp& __x, const _Tp& __y) const
            { return __x > __y; }
    };

    struct __less_equal
    {
        template<typename _Tp>
            bool operator()(const _Tp& __x, const _Tp& __y) const
            { return __x <= __y; }
    };

    struct __greater_equal
    {
        template<typename _Tp>
            bool operator()(const _Tp& __x, const _Tp& __y) const
            { return __x >= __y; }
    };

    // The few binary functions we miss.
    struct __atan2
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __x, const _Tp& __y) const
            { return atan2(__x, __y); }
    };

    struct __pow
    {
        template<typename _Tp>
            _Tp operator()(const _Tp& __x, const _Tp& __y) const
            { return pow(__x, __y); }
    };


    // We need these bits in order to recover the return type of
    // some functions/operators now that we're no longer using
    // function templates.
    template<typename, typename _Tp>
        struct __fun
        {
            typedef _Tp result_type;
        };

    // several specializations for relational operators.
    template<typename _Tp>
        struct __fun<__logical_not, _Tp>
        {
            typedef bool result_type;
        };

    template<typename _Tp>
        struct __fun<__logical_and, _Tp>
        {
            typedef bool result_type;
        };

    template<typename _Tp>
        struct __fun<__logical_or, _Tp>
        {
            typedef bool result_type;
        };

    template<typename _Tp>
        struct __fun<__less, _Tp>
        {
            typedef bool result_type;