Ichthyostega
3a491855e7
Well, finally. Lumiera Iterators were conceived as a concept from the very beginning, and this idea dates back even before C++11. Furthermore, over time some ''trait templates'' have been developed, to detect if some template argument might match the known pattern of functions associated with a Lumiera Iterator. Meanwhile this concept is used pervasively in the whole code base, and also the traits templates proved to be reliable. It therefore seems that the time is ripe to gradually introduce a genuine **concept** `lum_iter` I'll take a defensive approach here, since any mistake would lead to a massive breakage of compilation. The new concept is defined simply by delegating to to the tried-and-tested trait template, which is also renamed `can_IterForEach` ⟼ `can_LumieraIter` One immediate benefit is that the compiler is now able to select overloads based on that concept, which allows to drop the tricky selection of variants based on the SFINAE technique and `enable_if`. For validation, one very heavily used case of that pattern was switched in `lib/format-util.hpp', which notably lies in the code-path used by `util::join`
146 lines
3.5 KiB
C++
146 lines
3.5 KiB
C++
/*
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UtilCollection(Test) - helpers and shortcuts for working with collections
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Copyright (C)
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2012, 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 util-collection-test.cpp
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** unit test \ref UtilCollection_test
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*/
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#include "test/run.hpp"
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#include "lib/itertools.hpp"
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#include "lib/util-coll.hpp"
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#include "lib/iter-adapter.hpp"
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#include "lib/meta/trait.hpp"
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#include <boost/lexical_cast.hpp>
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#include <vector>
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using ::Test;
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using util::first;
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using util::last;
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using lib::meta::can_STL_ForEach;
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using lib::meta::can_LumieraIter;
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using lib::meta::can_STL_backIteration;
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using boost::lexical_cast;
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namespace util {
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namespace test {
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typedef std::vector<uint> VecI;
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typedef lib::RangeIter<VecI::iterator> RangeI;
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namespace{ // Test data and operations
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VecI
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someNumberz (uint count)
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{
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VecI numbers;
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numbers.reserve(count);
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while (count)
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numbers.push_back(count--);
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return numbers;
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}
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} // (End) test data and operations
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/*****************************************************************//**
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* @test verify some convenience shortcuts and helpers dealing
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* with Collections and sequences (Iterators).
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* - metafunctions to distinguish STL containers and Lumiera Iterators
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* - get the first element
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* - get the last element
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*/
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class UtilCollection_test : public Test
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{
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virtual void
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run (Arg arg)
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{
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verify_typeDetectors();
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uint NUM_ELMS = firstVal (arg, 20);
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VecI container = someNumberz (NUM_ELMS);
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RangeI iterator(container.begin(), container.end());
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verify_accessFirstLast (container, NUM_ELMS);
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verify_accessFirstLast (iterator, NUM_ELMS);
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verify_Min_Max (container, NUM_ELMS);
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verify_Min_Max (iterator, NUM_ELMS);
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}
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template<class COL>
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void
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verify_accessFirstLast (COL const& col, uint lim)
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{
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uint theFirst = lim;
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uint theLast = 1;
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CHECK (first(col) == theFirst);
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CHECK (last(col) == theLast);
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}
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template<class COL>
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void
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verify_Min_Max (COL const& col, uint lim)
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{
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uint expectedMax = lim;
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uint expectedMin = 1;
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CHECK (max (col) == expectedMax);
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CHECK (min (col) == expectedMin);
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COL empty;
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using Val = COL::value_type;
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CHECK (max (empty) == std::numeric_limits<Val>::min());
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CHECK (min (empty) == std::numeric_limits<Val>::max());
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}
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void
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verify_typeDetectors()
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{
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CHECK ( can_STL_ForEach<VecI>::value);
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CHECK ( can_STL_backIteration<VecI>::value);
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CHECK (!can_STL_ForEach<RangeI>::value);
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CHECK (!can_STL_backIteration<RangeI>::value);
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CHECK (!can_LumieraIter<VecI>::value);
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CHECK ( can_LumieraIter<RangeI>::value);
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}
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};
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LAUNCHER (UtilCollection_test, "unit common");
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}} // namespace util::test
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