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symfpu/core/ite.h
2018-05-10 13:59:01 +01:00

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1.9 KiB
C++

/*
** Copyright (C) 2018 Martin Brain
**
** This program 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 3 of the License, or
** (at your option) any later version.
**
** This program 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 program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
** ite.h
**
** Martin Brain
** martin.brain@cs.ox.ac.uk
** 03/12/14
**
** The handling of if-then-else depends on the type of both the condition
** (i.e. is it concrete or is it symbolic) and the type of the data
** (i.e. is it a symbolic class that wraps a tree node, is it a structure
** containing them, etc.). Some of the handling will work for any condition,
** any of the data, etc. So far not difficult in a language with multiple
** dispatch including type variables.
**
** However, we are using C++, so there are a few extra hoops to jump
** through. We declare ITEs as a struct containing a static function
** as then we can partially specialise templates of them.
** Specialisations of these are then given when appropriate types are
** introduced. Care must be taken with these to ensure that we don't
** get ambigious template instantiations.
**
*/
#ifndef SYMFPU_ITE
#define SYMFPU_ITE
namespace symfpu {
template <class prop, class data>
struct ite;
// To avoid the need for putting the types *everywhere* we use a
// helper function as C++ can perform type inference for functions
// but not classes.
template <class prop, class data>
const data ITE (const prop &c, const data &l, const data &r) {
return ite<prop, data>::iteOp(c, l, r);
}
}
#endif