Constexpr C++ 11 tribool

Enumerations
enum class	quickcpplib::_xxx::tribool::tribool : signed char {   quickcpplib::_xxx::tribool::tribool::false_ = -1 , quickcpplib::_xxx::tribool::tribool::true_ = 1 , quickcpplib::_xxx::tribool::tribool::other = 0 , quickcpplib::_xxx::tribool::tribool::indeterminate = 0 ,   quickcpplib::_xxx::tribool::tribool::unknown = 0 }
	A constexpr C++ 11 tribool. More...

Functions
constexpr tribool	quickcpplib::_xxx::tribool::make_tribool (int v) noexcept
	Explicit construction from some signed integer. <0 false, >0 true, 0 is other.
constexpr tribool	quickcpplib::_xxx::tribool::operator~ (tribool v) noexcept
	If tribool is true return false, if tribool is false return true, else return other.
constexpr tribool	quickcpplib::_xxx::tribool::operator& (tribool a, tribool b) noexcept
	If a is true and b is true, return true, if either is false return false, else return other.
constexpr tribool	quickcpplib::_xxx::tribool::operator| (tribool a, tribool b) noexcept
	If a is true or b is true, return true, if either is other return other, else return false.
constexpr bool	quickcpplib::_xxx::tribool::operator&& (tribool a, tribool b) noexcept
	If a is true and b is true, return true.
constexpr bool	quickcpplib::_xxx::tribool::operator|| (tribool a, tribool b) noexcept
	If a is true or b is true, return true.
constexpr bool	quickcpplib::_xxx::tribool::true_ (tribool a) noexcept
	Return true if tribool is true.
constexpr bool	quickcpplib::_xxx::tribool::false_ (tribool a) noexcept
	Return true if tribool is true.
constexpr bool	quickcpplib::_xxx::tribool::other (tribool a) noexcept
	Return true if tribool is other/indeterminate/unknown.
constexpr bool	quickcpplib::_xxx::tribool::indeterminate (tribool a) noexcept
	Return true if tribool is other/indeterminate/unknown.
constexpr bool	quickcpplib::_xxx::tribool::unknown (tribool a) noexcept
	Return true if tribool is other/indeterminate/unknown.

Detailed Description

This tries to be mostly compatible with Boost.Tribool, except it's written in C++ 11 and is 100% constexpr throughout by being a strongly typed enum. Note that other state is aliased to indeterminate for Boost.Tribool compatibility. It is also aliased to unknown.

Unlike Boost.Tribool this deliberately does not provide automatic conversion to bool. It was always questionable if code coped well with operator! != !operator bool anyway. Use the free functions true_(), false_(), other(), indeterminate() and unknown() to test the contents of this tribool.

For sorting, false < unknown < true. Same for max/min. STL functions operators << and >> for iostream are defined.

Enumeration Type Documentation

tribool

enum class quickcpplib::_xxx::tribool::tribool : signed char

strong

A constexpr C++ 11 tribool.

Enumerator
false_	False.
true_	True.
other	Other/Indeterminate/Unknown.
indeterminate	Other/Indeterminate/Unknown.
unknown	Other/Indeterminate/Unknown.

  {
    false_ = -1,        //!< False
    true_ = 1,          //!< True
    other = 0,          //!< Other/Indeterminate/Unknown
    indeterminate = 0,  //!< Other/Indeterminate/Unknown
    unknown = 0         //!< Other/Indeterminate/Unknown
  };

Function Documentation

make_tribool()

constexpr tribool quickcpplib::_xxx::tribool::make_tribool ( int  v )

inlineconstexprnoexcept

Explicit construction from some signed integer. <0 false, >0 true, 0 is other.

{ return v > 0 ? tribool::true_ : v < 0 ? tribool::false_ : tribool::other; }

operator~()

constexpr tribool quickcpplib::_xxx::tribool::operator~ ( tribool  v )

inlineconstexprnoexcept

If tribool is true return false, if tribool is false return true, else return other.

{ return static_cast<tribool>(-static_cast<signed char>(v)); }

operator&()

constexpr tribool quickcpplib::_xxx::tribool::operator& ( tribool  a, tribool  b  )

inlineconstexprnoexcept

If a is true and b is true, return true, if either is false return false, else return other.

{ return (a == tribool::true_ && b == tribool::true_) ? tribool::true_ : (a == tribool::false_ || b == tribool::false_) ? tribool::false_ : tribool::other; }

operator|()

constexpr tribool quickcpplib::_xxx::tribool::operator| ( tribool  a, tribool  b  )

inlineconstexprnoexcept

If a is true or b is true, return true, if either is other return other, else return false.

{ return (a == tribool::true_ || b == tribool::true_) ? tribool::true_ : (a == tribool::other || b == tribool::other) ? tribool::other : tribool::false_; }

operator&&()

constexpr bool quickcpplib::_xxx::tribool::operator&& ( tribool  a, tribool  b  )

inlineconstexprnoexcept

If a is true and b is true, return true.

{ return (a == tribool::true_ && b == tribool::true_); }

operator||()

constexpr bool quickcpplib::_xxx::tribool::operator|| ( tribool  a, tribool  b  )

inlineconstexprnoexcept

If a is true or b is true, return true.

{ return (a == tribool::true_ || b == tribool::true_); }

true_()

constexpr bool quickcpplib::_xxx::tribool::true_ ( tribool  a )

inlineconstexprnoexcept

Return true if tribool is true.

{ return a == tribool::true_; }

false_()

constexpr bool quickcpplib::_xxx::tribool::false_ ( tribool  a )

inlineconstexprnoexcept

Return true if tribool is true.

{ return a == tribool::false_; }

other()

constexpr bool quickcpplib::_xxx::tribool::other ( tribool  a )

inlineconstexprnoexcept

Return true if tribool is other/indeterminate/unknown.

{ return a == tribool::indeterminate; }

indeterminate()

constexpr bool quickcpplib::_xxx::tribool::indeterminate ( tribool  a )

inlineconstexprnoexcept

Return true if tribool is other/indeterminate/unknown.

{ return a == tribool::indeterminate; }

unknown()

constexpr bool quickcpplib::_xxx::tribool::unknown ( tribool  a )

inlineconstexprnoexcept

Return true if tribool is other/indeterminate/unknown.

{ return a == tribool::indeterminate; }