composes two functions into one
This commit is contained in:
parent
c70ffc4e64
commit
52f7ee11f7
1 changed files with 60 additions and 0 deletions
60
src/FbTk/Compose.hh
Normal file
60
src/FbTk/Compose.hh
Normal file
|
@ -0,0 +1,60 @@
|
|||
// Composer.hh
|
||||
// Copyright (c) 2003 Henrik Kinnunen (fluxgen at users.sourceforge.net)
|
||||
//
|
||||
// Permission is hereby granted, free of charge, to any person obtaining a
|
||||
// copy of this software and associated documentation files (the "Software"),
|
||||
// to deal in the Software without restriction, including without limitation
|
||||
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
|
||||
// and/or sell copies of the Software, and to permit persons to whom the
|
||||
// Software is furnished to do so, subject to the following conditions:
|
||||
//
|
||||
// The above copyright notice and this permission notice shall be included in
|
||||
// all copies or substantial portions of the Software.
|
||||
//
|
||||
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
||||
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
||||
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
||||
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
||||
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
||||
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
|
||||
// DEALINGS IN THE SOFTWARE.
|
||||
|
||||
// $Id: Compose.hh,v 1.1 2003/08/24 10:37:31 fluxgen Exp $
|
||||
|
||||
#ifndef FBTK_COMPOSE_HH
|
||||
#define FBTK_COMPOSE_HH
|
||||
|
||||
#include <functional>
|
||||
|
||||
namespace FbTk {
|
||||
|
||||
/// Composes two functions into one.
|
||||
/// Uses Arg for type B and then calls type A
|
||||
template <class A, class B>
|
||||
class Compose_base: public std::unary_function<typename B::argument_type, typename A::result_type> {
|
||||
public:
|
||||
typedef typename A::result_type ResultTypeA;
|
||||
typedef typename A::argument_type ArgumentTypeA;
|
||||
typedef typename B::result_type ResultTypeB;
|
||||
typedef typename B::argument_type ArgumentTypeB;
|
||||
|
||||
Compose_base(const A &a, const B &b):m_a(a), m_b(b) { }
|
||||
ResultTypeA operator () (const ArgumentTypeB &arg) const {
|
||||
return m_a(m_b(arg));
|
||||
}
|
||||
|
||||
private:
|
||||
A m_a;
|
||||
B m_b;
|
||||
};
|
||||
|
||||
// helper that creates a Compose_base
|
||||
template <typename A, typename B>
|
||||
inline Compose_base<A, B>
|
||||
Compose(const A& a, const B& b) {
|
||||
return Compose_base<A, B>(a, b);
|
||||
}
|
||||
|
||||
}; // namespace FbTk
|
||||
|
||||
#endif // FBTK_COMPOSE_HH
|
Loading…
Reference in a new issue