Ichthyostega
20392eee1c
This resolves an intricate problem related to metaprogramming with variadic templates and function signatures. Due to exceptional complexity, a direct solution was blocked for several years, and required a better organisation of the support code involved; several workarounds were developed, gradually leading to a transition path, which could now be completed in an focused clean-up effort over the last week. Metaprogramming with sequences of types is organised into three layers: - simple tasks can be solved with the standard facilities of the language, using pattern match with variadic template specialisations - the ''type-sequence'' construct `Types<T...>` takes the centre stage for the explicit definition of collections of types; it can be re-bound to other variadic templates and supports simple direct manipulation - for more elaborate and advanced processing tasks, a ''Loki-style type list'' can be obtained from a type-sequence, allowing to perform recursive list processing task with a technique similar to LISP.
200 lines
6.6 KiB
C++
200 lines
6.6 KiB
C++
/*
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FunctionClosure(Test) - appending, mixing and filtering typelists
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Copyright (C)
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2009, Hermann Vosseler <Ichthyostega@web.de>
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**Lumiera** is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by the
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Free Software Foundation; either version 2 of the License, or (at your
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option) any later version. See the file COPYING for further details.
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* *****************************************************************/
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/** @file function-closure-test.cpp
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** Testing a combination of std::function objects and metaprogramming.
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** Argument types will be extracted and represented as typelist, so they
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** can be manipulated at compile time. This test uses some test functions
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** and systematically applies or binds them to corresponding data tuples.
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** Moreover, closure objects will be constructed in various flavours,
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** combining a function object and a set of parameters.
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**
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** @see function-closure.hpp
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** @see control::CmdClosure real world usage example
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**
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*/
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#include "lib/test/run.hpp"
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#include "lib/test/test-helper.hpp"
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#include "lib/meta/typelist.hpp"
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#include "lib/meta/typelist-manip.hpp"
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#include "lib/meta/function.hpp"
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#include "lib/meta/function-closure.hpp"
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#include "meta/typelist-diagnostics.hpp"
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#include "meta/tuple-diagnostics.hpp"
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using std::string;
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namespace lib {
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namespace meta {
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namespace test {
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namespace { // test data
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using List1 = Types<Num<1>, Num<2>, Num<3> >::List;
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using List2 = Types<Num<5>, Num<6>, Num<7> >::List;
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/** special test fun
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* accepting the terrific Num types */
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template<char i,char ii, char iii>
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int
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getNumberz (Num<i> one, Num<ii> two, Num<iii> three)
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{
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return one.o_ + two.o_ + three.o_;
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}
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int fun0 () { return -1; }
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int fun1 (int i1) { return i1; }
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int fun2 (int i1, int i2) { return i1+i2; }
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int fun3 (int i1, int i2, int i3) { return i1+i2+i3; }
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} // (End) test data
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using func::bindArgTuple;
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/*********************************************************************//**
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* @test building a function closure for a given function or functor,
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* while arguments are passed in as tuple
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* - accessing signatures as typelists
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* - bind free function to tuple
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* - bind functor to tuple
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* @remark this test is _rather low-level_ and documents the construction
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* of the implementation; furthermore, most of this construction
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* was obsoleted by newer language features, notably std::apply
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* and the technique to unpack variadic-λ arguments.
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* What remains, is now largely a definition how to handle
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* function argument list signatures, to build suitable
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* argument tuple types by metaprogramming, and finally
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* to pass them to construct a binder.
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* @see function-composition-test.cpp (advanced features like partial application)
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*/
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class FunctionClosure_test : public Test
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{
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virtual void
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run (Arg)
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{
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verify_setup();
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check_signatureTypeManip();
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check_bindFree();
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check_bindFunc();
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}
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/** verify the test input data
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* @see TypeListManipl_test#check_diagnostics() for
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* explanation of the DISPLAY and EXPECT macros.
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*/
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void
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verify_setup()
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{
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DISPLAY (List1);
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DISPLAY (List2);
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;
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CHECK (6 == (getNumberz<1,2,3> (Num<1>(), Num<2>(), Num<3>())));
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CHECK (6 == (getNumberz<1,1,1> (Num<1>(), Num<1>(2), Num<1>(3))));
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}
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void
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check_signatureTypeManip ()
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{
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typedef int someFunc(Num<5>,Num<9>);
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typedef _Fun<someFunc>::Ret RetType; // should be int
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typedef _Fun<someFunc>::Args Args;
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DISPLAY (Args);
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typedef Prepend<Num<1>, Args>::Seq NewArgs; // manipulate the argument type(s)
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DISPLAY (NewArgs);
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typedef BuildFunType<RetType,NewArgs>::Sig NewSig; // re-build a new function signature
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NewSig& fun = getNumberz<1,5,9>; //...which is compatible to an existing real function signature!
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CHECK (1+5+9 == fun(Num<1>(), Num<5>(), Num<9>()));
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}
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void
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check_bindFree ()
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{
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cout << "\t:\n\t: ---Bind----\n";
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Tuple<Types<>> tup0 ;
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Tuple<Types<int>> tup1 (11);
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Tuple<Types<int,int>> tup2 (11,12);
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Tuple<Types<int,int,int>> tup3 (11,12,13);
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DUMPVAL (tup0);
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DUMPVAL (tup1);
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DUMPVAL (tup2);
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DUMPVAL (tup3);
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using BoundFun = function<int()>;
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BoundFun functor0 = bindArgTuple (fun0, tup0);
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BoundFun functor1 = bindArgTuple (fun1, tup1);
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BoundFun functor2 = bindArgTuple (fun2, tup2);
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BoundFun functor3 = bindArgTuple (fun3, tup3);
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CHECK (-1 == functor0() );
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CHECK (11 == functor1() );
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CHECK (11+12 == functor2() );
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CHECK (11+12+13 == functor3() );
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}
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void
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check_bindFunc ()
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{
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Tuple<Types<>> tup0 ;
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Tuple<Types<int>> tup1 (11);
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Tuple<Types<int,int>> tup2 (11,12);
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Tuple<Types<int,int,int>> tup3 (11,12,13);
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function<int()> unbound_functor0 (fun0);
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function<int(int)> unbound_functor1 (fun1);
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function<int(int,int)> unbound_functor2 (fun2);
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function<int(int,int,int)> unbound_functor3 (fun3);
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using BoundFun = function<int()>;
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BoundFun functor0 = bindArgTuple (unbound_functor0, tup0);
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BoundFun functor1 = bindArgTuple (unbound_functor1, tup1);
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BoundFun functor2 = bindArgTuple (unbound_functor2, tup2);
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BoundFun functor3 = bindArgTuple (unbound_functor3, tup3);
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CHECK (-1 == functor0() );
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CHECK (11 == functor1() );
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CHECK (11+12 == functor2() );
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CHECK (11+12+13 == functor3() );
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}
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};
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/** Register this test class... */
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LAUNCHER (FunctionClosure_test, "unit common");
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}}} // namespace lib::meta::test
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