More range functionality, unit tests. #46
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Julia 0.5 deprecates use of `symbol` instead of `Symbol`. This patch just substitutes the correct call.
* Tests for `math::pi`, `math::lerp`, `math::area_frustrum` and `math::volume_frustrum` * Fix `math:pi<long double>()`.
* New `filter` view: lazily selects based on predicate. * Generic `front` and `back` for sequences. * New rangeutil STL wrappers `stable_sort_by`, `all_of`, `any_of`. * Consolidate common utility unit testing structures into `tests/unit/common.hpp`
| template <typename I, bool = std::is_pointer<I>::value> | ||
| struct arrow { | ||
| using type = decltype(std::declval<I>().operator->()); | ||
| static type eval(I& x) { return x.operator->(); } |
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Could you use a const reference here, because it is return by value?
static type eval(const I& x) { return x.operator->(); }| template <typename I> | ||
| struct arrow<I, true> { | ||
| using type = I; | ||
| static type eval(I& x) { return x; } |
| static type eval(I& x) { return x; } | ||
| }; | ||
| } | ||
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A comment that briefly describes I, S and F is needed.
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| public: | ||
| using value_type = typename std::iterator_traits<I>::value_type; | ||
| using difference_type = typename std::iterator_traits<I>::difference_type; |
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This is a general question, because I haven't got so much experience implementing iterators. What is the purpose of defining iterator_category here? And why don't we inherit from std::iterator? I saw that this has been depricated in c++17, but I can't find any reasoning about why.
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I am sure that you will let me know when you review my iterator implementation in PR #45 :)
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iterator_category is added so that it can play nice with others; in particular, filter_iterator has useful semantics over a sequence described by input iterators, but then it itself no longer has forward iterator semantics, and this should be signalled to any generic code that uses it.
The committee's justification for the deprecation of std::iterator can be found here,
tl;dr: lacks clarity, and need to import typedefs from base class anyway to use them in-class.
| mutable I inner_; | ||
| S end_; | ||
| mutable bool ok_; | ||
| mutable uninitialized<F> f_; // always in initialized state post-construction |
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A comment on the rationale behind using uninitialized is needed, because it is not immediately obvious why to someone unfamiliar with the library.
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Will add (also for transform_iterator).
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* Add documentation of template parameters for `filter_iterator`. * Document use of `uninitalized<F>` for holding functional objects in `filter_iterator` and `transform_iterator`
Part of complex compartments feature update.
math::pi,math::lerp,math::area_frustrumandmath::volume_frustrummath:pi<long double>().filterview: lazily selects based on predicate.frontandbackfor sequences.stable_sort_by,all_of,any_of.tests/unit/common.hpp