diff -r 000000000000 -r e4d67989cc36 ossrv_pub/boost_apis/boost/logic/tribool.hpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/ossrv_pub/boost_apis/boost/logic/tribool.hpp Tue Feb 02 02:01:42 2010 +0200 @@ -0,0 +1,460 @@ +// Three-state boolean logic library + +// Copyright Douglas Gregor 2002-2004. Use, modification and +// distribution is subject to the Boost Software License, Version +// 1.0. (See accompanying file LICENSE_1_0.txt or copy at +// http://www.boost.org/LICENSE_1_0.txt) + + +// For more information, see http://www.boost.org +#ifndef BOOST_LOGIC_TRIBOOL_HPP +#define BOOST_LOGIC_TRIBOOL_HPP + +#include +#include +#include + +#if BOOST_WORKAROUND(_MSC_VER, >= 1200) +# pragma once +#endif + +namespace boost { namespace logic { + +/// INTERNAL ONLY +namespace detail { +/** + * INTERNAL ONLY + * + * \brief A type used only to uniquely identify the 'indeterminate' + * function/keyword. + */ +struct indeterminate_t +{ +#if BOOST_WORKAROUND(__BORLANDC__, < 0x0600) + char dummy_; // BCB would use 8 bytes by default +#endif +}; + +} // end namespace detail + +/** + * INTERNAL ONLY + * The type of the 'indeterminate' keyword. This has the same type as the + * function 'indeterminate' so that we can recognize when the keyword is + * used. + */ +typedef bool (*indeterminate_keyword_t)(tribool, detail::indeterminate_t); + +/** + * \brief Keyword and test function for the indeterminate tribool value + * + * The \c indeterminate function has a dual role. It's first role is + * as a unary function that tells whether the tribool value is in the + * "indeterminate" state. It's second role is as a keyword + * representing the indeterminate (just like "true" and "false" + * represent the true and false states). If you do not like the name + * "indeterminate", and would prefer to use a different name, see the + * macro \c BOOST_TRIBOOL_THIRD_STATE. + * + * \returns x.value == tribool::indeterminate_value + * \throws nothrow + */ +inline bool +indeterminate(tribool x, + detail::indeterminate_t dummy = detail::indeterminate_t()); + +/** + * \brief A 3-state boolean type. + * + * 3-state boolean values are either true, false, or + * indeterminate. + */ +class tribool +{ +private: + /// INTERNAL ONLY + struct dummy { + void nonnull() {}; + }; + + typedef void (dummy::*safe_bool)(); + +public: + /** + * Construct a new 3-state boolean value with the value 'false'. + * + * \throws nothrow + */ + tribool() : value(false_value) {} + + /** + * Construct a new 3-state boolean value with the given boolean + * value, which may be \c true or \c false. + * + * \throws nothrow + */ + tribool(bool value) : value(value? true_value : false_value) {} + + /** + * Construct a new 3-state boolean value with an indeterminate value. + * + * \throws nothrow + */ + tribool(indeterminate_keyword_t) : value(indeterminate_value) {} + + /** + * Use a 3-state boolean in a boolean context. Will evaluate true in a + * boolean context only when the 3-state boolean is definitely true. + * + * \returns true if the 3-state boolean is true, false otherwise + * \throws nothrow + */ + operator safe_bool() const + { + return value == true_value? &dummy::nonnull : 0; + } + + /** + * The actual stored value in this 3-state boolean, which may be false, true, + * or indeterminate. + */ + enum value_t { false_value, true_value, indeterminate_value } value; +}; + +// Check if the given tribool has an indeterminate value. Also doubles as a +// keyword for the 'indeterminate' value +inline bool indeterminate(tribool x, detail::indeterminate_t) +{ + return x.value == tribool::indeterminate_value; +} + +/** @defgroup logical Logical operations + */ +//@{ +/** + * \brief Computes the logical negation of a tribool + * + * \returns the logical negation of the tribool, according to the + * table: + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + *
!
+ *
false
true
true
false
indeterminate
indeterminate
+ * \throws nothrow + */ +inline tribool operator!(tribool x) +{ + return x.value == tribool::false_value? tribool(true) + :x.value == tribool::true_value? tribool(false) + :tribool(indeterminate); +} + +/** + * \brief Computes the logical conjuction of two tribools + * + * \returns the result of logically ANDing the two tribool values, + * according to the following table: + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + *
&&
false
true
indeterminate
false
false
false
false
true
false
true
indeterminate
indeterminate
false
indeterminate
indeterminate
+ * \throws nothrow + */ +inline tribool operator&&(tribool x, tribool y) +{ + if (static_cast(!x) || static_cast(!y)) + return false; + else if (static_cast(x) && static_cast(y)) + return true; + else + return indeterminate; +} + +/** + * \overload + */ +inline tribool operator&&(tribool x, bool y) +{ return y? x : tribool(false); } + +/** + * \overload + */ +inline tribool operator&&(bool x, tribool y) +{ return x? y : tribool(false); } + +/** + * \overload + */ +inline tribool operator&&(indeterminate_keyword_t, tribool x) +{ return !x? tribool(false) : tribool(indeterminate); } + +/** + * \overload + */ +inline tribool operator&&(tribool x, indeterminate_keyword_t) +{ return !x? tribool(false) : tribool(indeterminate); } + +/** + * \brief Computes the logical disjunction of two tribools + * + * \returns the result of logically ORing the two tribool values, + * according to the following table: + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + *
||
false
true
indeterminate
false
false
true
indeterminate
true
true
true
true
indeterminate
indeterminate
true
indeterminate
+ * \throws nothrow + */ +inline tribool operator||(tribool x, tribool y) +{ + if (static_cast(!x) && static_cast(!y)) + return false; + else if (static_cast(x) || static_cast(y)) + return true; + else + return indeterminate; +} + +/** + * \overload + */ +inline tribool operator||(tribool x, bool y) +{ return y? tribool(true) : x; } + +/** + * \overload + */ +inline tribool operator||(bool x, tribool y) +{ return x? tribool(true) : y; } + +/** + * \overload + */ +inline tribool operator||(indeterminate_keyword_t, tribool x) +{ return x? tribool(true) : tribool(indeterminate); } + +/** + * \overload + */ +inline tribool operator||(tribool x, indeterminate_keyword_t) +{ return x? tribool(true) : tribool(indeterminate); } +//@} + +/** + * \brief Compare tribools for equality + * + * \returns the result of comparing two tribool values, according to + * the following table: + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + *
==
false
true
indeterminate
false
true
false
indeterminate
true
false
true
indeterminate
indeterminate
indeterminate
indeterminate
indeterminate
+ * \throws nothrow + */ +inline tribool operator==(tribool x, tribool y) +{ + if (indeterminate(x) || indeterminate(y)) + return indeterminate; + else + return x && y || !x && !y; +} + +/** + * \overload + */ +inline tribool operator==(tribool x, bool y) { return x == tribool(y); } + +/** + * \overload + */ +inline tribool operator==(bool x, tribool y) { return tribool(x) == y; } + +/** + * \overload + */ +inline tribool operator==(indeterminate_keyword_t, tribool x) +{ return tribool(indeterminate) == x; } + +/** + * \overload + */ +inline tribool operator==(tribool x, indeterminate_keyword_t) +{ return tribool(indeterminate) == x; } + +/** + * \brief Compare tribools for inequality + * + * \returns the result of comparing two tribool values for inequality, + * according to the following table: + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + *
!=
false
true
indeterminate
false
false
true
indeterminate
true
true
false
indeterminate
indeterminate
indeterminate
indeterminate
indeterminate
+ * \throws nothrow + */ +inline tribool operator!=(tribool x, tribool y) +{ + if (indeterminate(x) || indeterminate(y)) + return indeterminate; + else + return !(x && y || !x && !y); +} + +/** + * \overload + */ +inline tribool operator!=(tribool x, bool y) { return x != tribool(y); } + +/** + * \overload + */ +inline tribool operator!=(bool x, tribool y) { return tribool(x) != y; } + +/** + * \overload + */ +inline tribool operator!=(indeterminate_keyword_t, tribool x) +{ return tribool(indeterminate) != x; } + +/** + * \overload + */ +inline tribool operator!=(tribool x, indeterminate_keyword_t) +{ return x != tribool(indeterminate); } + +} } // end namespace boost::logic + +// Pull tribool and indeterminate into namespace "boost" +namespace boost { + using logic::tribool; + using logic::indeterminate; +} + +/** + * \brief Declare a new name for the third state of a tribool + * + * Use this macro to declare a new name for the third state of a + * tribool. This state can have any number of new names (in addition + * to \c indeterminate), all of which will be equivalent. The new name will be + * placed in the namespace in which the macro is expanded. + * + * Example: + * BOOST_TRIBOOL_THIRD_STATE(true_or_false) + * + * tribool x(true_or_false); + * // potentially set x + * if (true_or_false(x)) { + * // don't know what x is + * } + */ +#define BOOST_TRIBOOL_THIRD_STATE(Name) \ +inline bool \ +Name(boost::logic::tribool x, \ + boost::logic::detail::indeterminate_t dummy = \ + boost::logic::detail::indeterminate_t()) \ +{ return x.value == boost::logic::tribool::indeterminate_value; } + +#endif // BOOST_LOGIC_TRIBOOL_HPP +