New Core Tutorial

git-svn-id: svn://ultimatepp.org/upp/trunk@10538 f0d560ea-af0d-0410-9eb7-867de7ffcac7

tutorial/CoreTutorial/Ranges.cpp

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+#include "Tutorial.h"
+
+void Range()
+{
+	/// .Range
+	
+	/// Unlike STL, which interface algorithms with data using `begin` / `end` pair, U++ algorithms
+	/// usually work on %Ranges%. Range is an object that has `begin` / `end` methods providing
+	/// random access to elements (all U++ containers are random access), `operator[]` and
+	/// `GetCount` method.
+	
+	/// Obviously, U++ containers are ranges:
+	
+	Vector<int> x = { 1, 2, 3, 4, 5, 1, 2, 3, 4 };
+	
+	DUMP(FindIndex(x, 2)); // FindIndex is a trivial algorithm that does linear search
+	
+	/// If you want the algorithm to run on part of container only, you can use `SubRange`
+	/// instance:
+	
+	DUMP(SubRange(x, 3, 6));
+	DUMP(FindIndex(SubRange(x, 3, 6), 4));
+	
+	/// As a side-job, SubRange can also be created from 'begin' / 'end' pair, thus e.g.
+	/// allowing algorithms to work on C arrays:
+	
+	int a[] = { 1, 22, 4, 2, 8 };
+	
+	auto ar = SubRange(std::begin(a), std::end(a));
+	
+	DUMP(ar);
+	
+	///
+	
+	Sort(ar);
+	DUMP(ar);
+
+	/// There are some macro aliases that make type management of ranges easier:
+
+	DUMP(typeid(ValueTypeOf<decltype(x)>).name());
+	DUMP(typeid(ValueTypeOf<decltype(SubRange(x, 1, 1))>).name());
+	DUMP(typeid(IteratorOf<decltype(x)>).name());
+	DUMP(typeid(ConstIteratorOf<decltype(SubRange(x, 1, 1))>).name());
+	DUMP(typeid(SubRangeOf<Vector<int>>).name());
+	
+	/// While containers themselves and SubRange are the two most common range types, U++ has two
+	/// special ranges. `ConstRange` simply provides the range of single value:
+	
+	DUMP(ConstRange(1, 10));
+	
+	/// `ViewRange` picks a source range and `Vector` of integer indices a provides a view of
+	/// source range through this `Vector`:
+	
+	Vector<int> h{ 2, 4, 0 };
+	
+	DUMP(ViewRange(x, clone(h)));
+
+	///
+	
+	Sort(ViewRange(x, clone(h)));
+	DUMP(ViewRange(x, clone(h)));
+	DUMP(x);
+	
+	/// Finally `FilterRange` creates a subrange of elements satisfying certain condition:
+	
+	DUMP(FilterRange(x, [](int x) { return x > 3; }));
+	
+	///
+}