mirror of
https://github.com/boostorg/utility.git
synced 2025-11-04 10:21:48 +01:00
4f9b0bcb9b
does not get called, it should not be checked for this error. This showed up when using an iterator with value_type=int. [SVN r7813]
564 lines
19 KiB
C++
564 lines
19 KiB
C++
// Boost operators.hpp header file ----------------------------------------//
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// (C) Copyright David Abrahams 1999. Permission to copy, use,
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// modify, sell and distribute this software is granted provided this
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// copyright notice appears in all copies. This software is provided
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// "as is" without express or implied warranty, and with no claim as
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// to its suitability for any purpose.
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// (C) Copyright Jeremy Siek 1999. Permission to copy, use, modify,
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// sell and distribute this software is granted provided this
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// copyright notice appears in all copies. This software is provided
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// "as is" without express or implied warranty, and with no claim as
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// to its suitability for any purpose.
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// See http://www.boost.org for most recent version including documentation.
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// Revision History
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// 04 Jul 00 Fixed NO_OPERATORS_IN_NAMESPACE bugs, major cleanup and
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// refactoring of compiler workarounds, additional documentation
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// (Alexy Gurtovoy and Mark Rodgers with some help and prompting from
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// Dave Abrahams)
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// 28 Jun 00 General cleanup and integration of bugfixes from Mark Rodgers and
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// Jeremy Siek (Dave Abrahams)
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// 20 Jun 00 Changes to accommodate Borland C++Builder 4 and Borland C++ 5.5
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// (Mark Rodgers)
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// 20 Jun 00 Minor fixes to the prior revision (Aleksey Gurtovoy)
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// 10 Jun 00 Support for the base class chaining technique was added
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// (Aleksey Gurtovoy). See documentation and the comments below
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// for the details.
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// 12 Dec 99 Initial version with iterator operators (Jeremy Siek)
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// 18 Nov 99 Change name "divideable" to "dividable", remove unnecessary
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// specializations of dividable, subtractable, modable (Ed Brey)
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// 17 Nov 99 Add comments (Beman Dawes)
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// Remove unnecessary specialization of operators<> (Ed Brey)
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// 15 Nov 99 Fix less_than_comparable<T,U> second operand type for first two
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// operators.(Beman Dawes)
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// 12 Nov 99 Add operators templates (Ed Brey)
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// 11 Nov 99 Add single template parameter version for compilers without
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// partial specialization (Beman Dawes)
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// 10 Nov 99 Initial version
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// 10 Jun 00:
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// An additional optional template parameter was added to most of
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// operator templates to support the base class chaining technique (see
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// documentation for the details). Unfortunately, a straightforward
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// implementation of this change would have broken compatibility with the
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// previous version of the library by making it impossible to use the same
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// template name (e.g. 'addable') for both the 1- and 2-argument versions of
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// an operator template. This implementation solves the backward-compatibility
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// issue at the cost of some simplicity.
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//
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// One of the complications is an existence of special auxiliary class template
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// 'is_chained_base<>' (see 'detail' namespace below), which is used
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// to determine whether its template parameter is a library's operator template
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// or not. You have to specialize 'is_chained_base<>' for each new
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// operator template you add to the library.
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//
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// However, most of the non-trivial implementation details are hidden behind
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// several local macros defined below, and as soon as you understand them,
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// you understand the whole library implementation.
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#ifndef BOOST_OPERATORS_HPP
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#define BOOST_OPERATORS_HPP
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#include <boost/config.hpp>
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#include <boost/iterator.hpp>
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#if defined(__sgi) && !defined(__GNUC__)
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#pragma set woff 1234
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#endif
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#if defined(BOOST_MSVC)
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# pragma warning( disable : 4284 ) // complaint about return type of
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#endif // operator-> not begin a UDT
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namespace boost {
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namespace detail {
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class empty_base {};
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} // namespace detail
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} // namespace boost
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// In this section we supply the xxxx1 and xxxx2 forms of the operator
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// templates, which are explicitly targeted at the 1-type-argument and
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// 2-type-argument operator forms, respectively. Some compilers get confused
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// when inline friend functions are overloaded in namespaces other than the
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// global namespace. When BOOST_NO_OPERATORS_IN_NAMESPACE is defined, all of
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// these templates must go in the global namespace.
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#ifndef BOOST_NO_OPERATORS_IN_NAMESPACE
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namespace boost
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{
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#endif
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// Basic operator classes (contributed by Dave Abrahams) ------------------//
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// Note that friend functions defined in a class are implicitly inline.
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// See the C++ std, 11.4 [class.friend] paragraph 5
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template <class T, class U, class B = ::boost::detail::empty_base>
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struct less_than_comparable2 : B
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{
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friend bool operator<=(const T& x, const U& y) { return !(x > y); }
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friend bool operator>=(const T& x, const U& y) { return !(x < y); }
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friend bool operator>(const U& x, const T& y) { return y < x; }
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friend bool operator<(const U& x, const T& y) { return y > x; }
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friend bool operator<=(const U& x, const T& y) { return !(y < x); }
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friend bool operator>=(const U& x, const T& y) { return !(y > x); }
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};
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template <class T, class B = ::boost::detail::empty_base>
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struct less_than_comparable1 : B
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{
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friend bool operator>(const T& x, const T& y) { return y < x; }
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friend bool operator<=(const T& x, const T& y) { return !(y < x); }
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friend bool operator>=(const T& x, const T& y) { return !(x < y); }
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};
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template <class T, class U, class B = ::boost::detail::empty_base>
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struct equality_comparable2 : B
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{
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friend bool operator==(const U& y, const T& x) { return x == y; }
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friend bool operator!=(const U& y, const T& x) { return !(x == y); }
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friend bool operator!=(const T& y, const U& x) { return !(y == x); }
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};
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template <class T, class B = ::boost::detail::empty_base>
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struct equality_comparable1 : B
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{
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friend bool operator!=(const T& x, const T& y) { return !(x == y); }
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};
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template <class T, class U, class B = ::boost::detail::empty_base>
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struct multipliable2 : B
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{
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friend T operator*(T x, const U& y) { return x *= y; }
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friend T operator*(const U& y, T x) { return x *= y; }
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};
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template <class T, class B = ::boost::detail::empty_base>
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struct multipliable1 : B
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{
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friend T operator*(T x, const T& y) { return x *= y; }
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};
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template <class T, class U, class B = ::boost::detail::empty_base>
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struct addable2 : B
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{
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friend T operator+(T x, const U& y) { return x += y; }
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friend T operator+(const U& y, T x) { return x += y; }
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};
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template <class T, class B = ::boost::detail::empty_base>
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struct addable1 : B
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{
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friend T operator+(T x, const T& y) { return x += y; }
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};
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template <class T, class U, class B = ::boost::detail::empty_base>
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struct subtractable2 : B
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{
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friend T operator-(T x, const U& y) { return x -= y; }
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};
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template <class T, class B = ::boost::detail::empty_base>
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struct subtractable1 : B
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{
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friend T operator-(T x, const T& y) { return x -= y; }
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};
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template <class T, class U, class B = ::boost::detail::empty_base>
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struct dividable2 : B
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{
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friend T operator/(T x, const U& y) { return x /= y; }
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};
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template <class T, class B = ::boost::detail::empty_base>
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struct dividable1 : B
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{
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friend T operator/(T x, const T& y) { return x /= y; }
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};
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template <class T, class U, class B = ::boost::detail::empty_base>
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struct modable2 : B
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{
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friend T operator%(T x, const U& y) { return x %= y; }
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};
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template <class T, class B = ::boost::detail::empty_base>
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struct modable1 : B
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{
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friend T operator%(T x, const T& y) { return x %= y; }
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};
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template <class T, class U, class B = ::boost::detail::empty_base>
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struct xorable2 : B
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{
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friend T operator^(T x, const U& y) { return x ^= y; }
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friend T operator^(const U& y, T x) { return x ^= y; }
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};
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template <class T, class B = ::boost::detail::empty_base>
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struct xorable1 : B
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{
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friend T operator^(T x, const T& y) { return x ^= y; }
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};
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template <class T, class U, class B = ::boost::detail::empty_base>
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struct andable2 : B
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{
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friend T operator&(T x, const U& y) { return x &= y; }
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friend T operator&(const U& y, T x) { return x &= y; }
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};
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template <class T, class B = ::boost::detail::empty_base>
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struct andable1 : B
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{
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friend T operator&(T x, const T& y) { return x &= y; }
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};
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template <class T, class U, class B = ::boost::detail::empty_base>
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struct orable2 : B
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{
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friend T operator|(T x, const U& y) { return x |= y; }
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friend T operator|(const U& y, T x) { return x |= y; }
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};
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template <class T, class B = ::boost::detail::empty_base>
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struct orable1 : B
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{
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friend T operator|(T x, const T& y) { return x |= y; }
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};
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// incrementable and decrementable contributed by Jeremy Siek
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template <class T, class B = ::boost::detail::empty_base>
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struct incrementable : B
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{
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friend T operator++(T& x, int)
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{
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incrementable_type tmp(x);
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++x;
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return tmp;
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}
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private: // The use of this typedef works around a Borland bug
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typedef T incrementable_type;
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};
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template <class T, class B = ::boost::detail::empty_base>
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struct decrementable : B
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{
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friend T operator--(T& x, int)
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{
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decrementable_type tmp(x);
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--x;
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return tmp;
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}
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private: // The use of this typedef works around a Borland bug
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typedef T decrementable_type;
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};
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// Iterator operator classes (contributed by Jeremy Siek) ------------------//
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template <class T, class P, class B = ::boost::detail::empty_base>
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struct dereferenceable : B
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{
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P operator->() const
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{
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return &*static_cast<const T&>(*this);
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}
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};
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template <class T, class I, class R, class B = ::boost::detail::empty_base>
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struct indexable : B
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{
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R operator[](I n) const
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{
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return *(static_cast<const T&>(*this) + n);
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}
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};
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#ifndef BOOST_NO_OPERATORS_IN_NAMESPACE
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} // namespace boost
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#endif // BOOST_NO_OPERATORS_IN_NAMESPACE
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// BOOST_IMPORT_TEMPLATE1/BOOST_IMPORT_TEMPLATE2 -
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//
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// When BOOST_NO_OPERATORS_IN_NAMESPACE is defined we need a way to import an
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// operator template into the boost namespace. BOOST_IMPORT_TEMPLATE1 is used
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// for one-argument forms of operator templates; BOOST_IMPORT_TEMPLATE2 for
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// two-argument forms. Note that these macros expect to be invoked from within
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// boost.
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#if defined(BOOST_NO_OPERATORS_IN_NAMESPACE)
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# if defined(BOOST_NO_USING_TEMPLATE)
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// Because a Borland C++ 5.5 bug prevents a using declaration from working,
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// we are forced to use inheritance for that compiler.
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# define BOOST_IMPORT_TEMPLATE2(template_name) \
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template <class T, class U, class B = ::boost::detail::empty_base> \
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struct template_name : ::template_name<T, U, B> {};
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# define BOOST_IMPORT_TEMPLATE1(template_name) \
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template <class T, class B = ::boost::detail::empty_base> \
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struct template_name : ::template_name<T, B> {};
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# else
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// Otherwise, bring the names in with a using-declaration to avoid
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// stressing the compiler
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# define BOOST_IMPORT_TEMPLATE2(template_name) using ::template_name;
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# define BOOST_IMPORT_TEMPLATE1(template_name) using ::template_name;
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# endif // BOOST_NO_USING_TEMPLATE
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#else // !BOOST_NO_OPERATORS_IN_NAMESPACE
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// The template is already in boost so we have nothing to do.
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# define BOOST_IMPORT_TEMPLATE2(template_name)
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# define BOOST_IMPORT_TEMPLATE1(template_name)
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#endif // BOOST_NO_OPERATORS_IN_NAMESPACE
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//
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// Here's where we put it all together, defining the xxxx forms of the templates
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// in namespace boost. We also define specializations of is_chained_base<> for
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// the xxxx, xxxx1, and xxxx2 templates, importing them into boost:: as
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// neccessary.
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//
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#if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
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// is_chained_base<> - a traits class used to distinguish whether an operator
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// template argument is being used for base class chaining, or is specifying a
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// 2nd argument type.
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namespace boost {
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// A type parameter is used instead of a plain bool because Borland's compiler
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// didn't cope well with the more obvious non-type template parameter.
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namespace detail {
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struct true_t {};
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struct false_t {};
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} // namespace detail
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// Unspecialized version assumes that most types are not being used for base
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// class chaining. We specialize for the operator templates defined in this
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// library.
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template<class T> struct is_chained_base {
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typedef ::boost::detail::false_t value;
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};
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} // namespace boost
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// Import a 2-type-argument operator template into boost (if neccessary) and
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// provide a specialization of 'is_chained_base<>' for it.
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# define BOOST_OPERATOR_TEMPLATE2(template_name2) \
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BOOST_IMPORT_TEMPLATE2(template_name2) \
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template<class T, class U, class B> \
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struct is_chained_base< ::boost::template_name2<T, U, B> > { \
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typedef ::boost::detail::true_t value; \
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};
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// Import a 1-type-argument operator template into boost (if neccessary) and
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// provide a specialization of 'is_chained_base<>' for it.
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# define BOOST_OPERATOR_TEMPLATE1(template_name1) \
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BOOST_IMPORT_TEMPLATE1(template_name1) \
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template<class T, class B> \
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struct is_chained_base< ::boost::template_name1<T, B> > { \
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typedef ::boost::detail::true_t value; \
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};
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// BOOST_OPERATOR_TEMPLATE(template_name) defines template_name<> such that it
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// can be used for specifying both 1-argument and 2-argument forms. Requires the
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// existence of two previously defined class templates named '<template_name>1'
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// and '<template_name>2' which must implement the corresponding 1- and 2-
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// argument forms.
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//
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// The template type parameter O == is_chained_base<U>::value is used to
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// distinguish whether the 2nd argument to <template_name> is being used for
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// base class chaining from another boost operator template or is describing a
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// 2nd operand type. O == true_t only when U is actually an another operator
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// template from the library. Partial specialization is used to select an
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// implementation in terms of either '<template_name>1' or '<template_name>2'.
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//
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# define BOOST_OPERATOR_TEMPLATE(template_name) \
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template <class T \
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,class U = T \
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,class B = ::boost::detail::empty_base \
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,class O = typename is_chained_base<U>::value \
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> \
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struct template_name : template_name##2<T, U, B> {}; \
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\
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template<class T, class U, class B> \
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struct template_name<T, U, B, ::boost::detail::true_t> \
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: template_name##1<T, U> {}; \
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\
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template <class T, class B> \
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struct template_name<T, T, B, ::boost::detail::false_t> \
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: template_name##1<T, B> {}; \
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\
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template<class T, class U, class B, class O> \
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struct is_chained_base< ::boost::template_name<T, U, B, O> > { \
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typedef ::boost::detail::true_t value; \
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}; \
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\
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BOOST_OPERATOR_TEMPLATE2(template_name##2) \
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BOOST_OPERATOR_TEMPLATE1(template_name##1)
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#else // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
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# define BOOST_OPERATOR_TEMPLATE2(template_name2) \
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BOOST_IMPORT_TEMPLATE2(template_name2)
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# define BOOST_OPERATOR_TEMPLATE1(template_name1) \
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BOOST_IMPORT_TEMPLATE1(template_name1)
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// In this case we can only assume that template_name<> is equivalent to the
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// more commonly needed template_name1<> form.
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# define BOOST_OPERATOR_TEMPLATE(template_name) \
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template <class T, class B = ::boost::detail::empty_base> \
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struct template_name : template_name##1<T, B> {};
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#endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
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namespace boost {
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BOOST_OPERATOR_TEMPLATE(less_than_comparable)
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BOOST_OPERATOR_TEMPLATE(equality_comparable)
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BOOST_OPERATOR_TEMPLATE(multipliable)
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BOOST_OPERATOR_TEMPLATE(addable)
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BOOST_OPERATOR_TEMPLATE(subtractable)
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BOOST_OPERATOR_TEMPLATE(dividable)
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BOOST_OPERATOR_TEMPLATE(modable)
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BOOST_OPERATOR_TEMPLATE(xorable)
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BOOST_OPERATOR_TEMPLATE(andable)
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BOOST_OPERATOR_TEMPLATE(orable)
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BOOST_OPERATOR_TEMPLATE1(incrementable)
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BOOST_OPERATOR_TEMPLATE1(decrementable)
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BOOST_OPERATOR_TEMPLATE2(dereferenceable)
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// indexable doesn't follow the patterns above (it has 4 template arguments), so
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// we just write out the compiler hacks explicitly.
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#ifdef BOOST_NO_OPERATORS_IN_NAMESPACE
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# ifdef BOOST_NO_USING_TEMPLATE
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template <class T, class I, class R, class B = ::boost::detail::empty_base>
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struct indexable : ::indexable<T,I,R,B> {};
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# else
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using ::indexable;
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# endif
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#endif
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#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
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template <class T, class I, class R, class B>
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struct is_chained_base< ::boost::indexable<T, I, R, B> > {
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typedef ::boost::detail::true_t operator_template_type;
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};
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#endif
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#undef BOOST_OPERATOR_TEMPLATE
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#undef BOOST_OPERATOR_TEMPLATE2
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#undef BOOST_OPERATOR_TEMPLATE1
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#undef BOOST_IMPORT_TEMPLATE1
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#undef BOOST_IMPORT_TEMPLATE2
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// The following 'operators' classes can only be used portably if the derived class
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// declares ALL of the required member operators.
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template <class T, class U>
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struct operators2
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: less_than_comparable2<T,U
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, equality_comparable2<T,U
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|
, addable2<T,U
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, subtractable2<T,U
|
|
, multipliable2<T,U
|
|
, dividable2<T,U
|
|
, modable2<T,U
|
|
, orable2<T,U
|
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, andable2<T,U
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|
, xorable2<T,U
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|
> > > > > > > > > > {};
|
|
|
|
#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
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|
template <class T, class U = T>
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struct operators : operators2<T, U> {};
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|
|
|
template <class T> struct operators<T, T>
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|
#else
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|
template <class T> struct operators
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|
#endif
|
|
: less_than_comparable<T
|
|
, equality_comparable<T
|
|
, addable<T
|
|
, subtractable<T
|
|
, multipliable<T
|
|
, dividable<T
|
|
, modable<T
|
|
, orable<T
|
|
, andable<T
|
|
, xorable<T
|
|
, incrementable<T
|
|
, decrementable<T
|
|
> > > > > > > > > > > > {};
|
|
|
|
// Iterator helper classes (contributed by Jeremy Siek) -------------------//
|
|
template <class T,
|
|
class V,
|
|
class D = std::ptrdiff_t,
|
|
class P = V*,
|
|
class R = V&>
|
|
struct forward_iterator_helper
|
|
: equality_comparable<T
|
|
, incrementable<T
|
|
, dereferenceable<T,P
|
|
, boost::iterator<std::forward_iterator_tag, V, D
|
|
> > > > {};
|
|
|
|
template <class T,
|
|
class V,
|
|
class D = std::ptrdiff_t,
|
|
class P = V*,
|
|
class R = V&>
|
|
struct bidirectional_iterator_helper
|
|
: equality_comparable<T
|
|
, incrementable<T
|
|
, decrementable<T
|
|
, dereferenceable<T,P
|
|
, boost::iterator<std::bidirectional_iterator_tag, V, D
|
|
> > > > > {};
|
|
|
|
template <class T,
|
|
class V,
|
|
class D = std::ptrdiff_t,
|
|
class P = V*,
|
|
class R = V&>
|
|
struct random_access_iterator_helper
|
|
: equality_comparable<T
|
|
, less_than_comparable<T
|
|
, incrementable<T
|
|
, decrementable<T
|
|
, dereferenceable<T,P
|
|
, addable2<T,D
|
|
, subtractable2<T,D
|
|
, indexable<T,D,R
|
|
, boost::iterator<std::random_access_iterator_tag, V, D
|
|
> > > > > > > > >
|
|
{
|
|
#ifndef __BORLANDC__
|
|
friend D requires_difference_operator(const T& x, const T& y) {
|
|
return x - y;
|
|
}
|
|
#endif
|
|
}; // random_access_iterator_helper
|
|
|
|
} // namespace boost
|
|
|
|
#if defined(__sgi) && !defined(__GNUC__)
|
|
#pragma reset woff 1234
|
|
#endif
|
|
|
|
#endif // BOOST_OPERATORS_HPP
|