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Diffstat (limited to 'ml/dlib/dlib/unordered_pair.h')
| -rw-r--r-- | ml/dlib/dlib/unordered_pair.h | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/ml/dlib/dlib/unordered_pair.h b/ml/dlib/dlib/unordered_pair.h new file mode 100644 index 000000000..9ea75b912 --- /dev/null +++ b/ml/dlib/dlib/unordered_pair.h @@ -0,0 +1,176 @@ +// Copyright (C) 2010 Davis E. King (davis@dlib.net) +// License: Boost Software License See LICENSE.txt for the full license. +#ifndef DLIB_UNORDERED_PAiR_Hh_ +#define DLIB_UNORDERED_PAiR_Hh_ + +#include "serialize.h" + +namespace dlib +{ + +// ---------------------------------------------------------------------------------------- + + template < + typename T + > + struct unordered_pair + { + /*! + REQUIREMENTS ON T + T must be default constructable, copyable, and comparable using + operator < and == + + WHAT THIS OBJECT REPRESENTS + This object is very similar to the std::pair struct except unordered_pair + is only capable of representing an unordered set of two items rather than + an ordered list of two items like std::pair. + + This is best illustrated by example. Suppose we have the following + five variables: + std::pair<int,int> p1(1, 5), p2(5,1); + unordered_pair<int> up1(1,5), up2(5,1), up3(6,7); + + Then it is the case that: + up1 == up2 + up1 != up3 + p1 != p2 + + So the unordered_pair doesn't care about the order of the arguments. + In this case, up1 and up2 are both equivalent. + + !*/ + + typedef T type; + typedef T first_type; + typedef T second_type; + + const T first; + const T second; + + unordered_pair() : first(), second() + /*! + ensures + - #first and #second are default initialized + !*/ {} + + unordered_pair( + const T& a, + const T& b + ) : + first( a < b ? a : b), + second(a < b ? b : a) + /*! + ensures + - #first <= #second + - #first and #second contain copies of the items a and b. + !*/ {} + + template <typename U> + unordered_pair ( + const unordered_pair <U>& p + ) : + first(p.first), + second(p.second) + /*! + ensures + - #*this is a copy of p + !*/ {} + + unordered_pair& operator= ( + const unordered_pair& item + ) + /*! + ensures + - #*this == item + !*/ + { + const_cast<T&>(first) = item.first; + const_cast<T&>(second) = item.second; + return *this; + } + }; + +// ---------------------------------------------------------------------------------------- + + template <typename T> + bool operator==(const unordered_pair<T>& a, const unordered_pair <T>& b) + { + return a.first == b.first && a.second == b.second; + } + + template <typename T> + bool operator!=(const unordered_pair<T>& a, const unordered_pair <T>& b) + { + return !(a == b); + } + + template <typename T> + bool operator<(const unordered_pair<T>& a, const unordered_pair<T>& b) + { + return (a.first < b.first || (!(b.first < a.first) && a.second < b.second)); + } + + template <typename T> + bool operator>(const unordered_pair<T>& a, const unordered_pair <T>& b) + { + return b < a; + } + + template <typename T> + bool operator<=(const unordered_pair<T>& a, const unordered_pair <T>& b) + { + return !(b < a); + } + + template <typename T> + bool operator>=(const unordered_pair<T>& a, const unordered_pair <T>& b) + { + return !(a < b); + } + + template <typename T> + unordered_pair<T> make_unordered_pair (const T& a, const T& b) + { + return unordered_pair<T>(a,b); + } + +// ---------------------------------------------------------------------------------------- + + template <typename T> + void serialize ( + const unordered_pair<T>& item, + std::ostream& out + ) + { + try + { + serialize(item.first,out); + serialize(item.second,out); + } + catch (serialization_error& e) + { throw serialization_error(e.info + "\n while serializing object of type unordered_pair"); } + } + + template <typename T> + void deserialize ( + unordered_pair<T>& item, + std::istream& in + ) + { + try + { + T a, b; + deserialize(a,in); + deserialize(b,in); + item = make_unordered_pair(a,b); + } + catch (serialization_error& e) + { throw serialization_error(e.info + "\n while deserializing object of type unordered_pair"); } + } + +// ---------------------------------------------------------------------------------------- + +} + +#endif // DLIB_UNORDERED_PAiR_Hh_ + |