(1) static bool eq( char_type a, char_type b ); (until C++11) static constexpr bool eq( char_type a, char_type b ); (since C++11) (2) static bool lt( char_type a, char_type b ); (until C++11) static constexpr bool lt( char_type a, char_type b ); (since C++11) Compares two characters. 1) Compares a and b for equality. 2) Compares a and b in such a way that they are totally ordered. For the char specialization, eq and lt are defined identically to the built-in operato

iterator find( const Key& key ); (1) const_iterator find( const Key& key ) const; (2) 1,2) Finds an element with key equivalent to key. Parameters key - key value of the element to search for Return value Iterator to an element with key equivalent to key. If no such element is found, past-the-end (see end()) iterator is returned. Complexity Constant on average, worst case linear in the size of the container. Example #include <iostream> #includ

void seed(); (1) (since C++11) void seed( result_type value ); (2) (since C++11) template< class Sseq > void seed( Sseq& seq ); (3) (since C++11) Reinitializes the internal state of the underlying engine using a new seed value. 1) Seeds the underlying engine with the default seed value. Effectively calls e.seed(), where e is the underlying engine. 2) Seeds the underlying engine with the seed value s. Effectively calls e.seed(value), where e is the underlying eng

Defined in header <type_traits> template< class T > struct make_unsigned; (since C++11) If T is an integral (except bool) or enumeration type, provides the member typedef type which is the unsigned integer type corresponding to T, with the same cv-qualifiers. Otherwise, the behavior is undefined. Member types Name Definition type the unsigned integer type corresponding to T Helper types template< class T > using make_unsigned_t = typename make_u

Defined in header <locale> public: string_type truename() const; (1) public: string_type falsename() const; (2) protected: virtual string_type do_truename() const; (3) protected: virtual string_type do_falsename() const; (4) 1-2) Public member function, calls the member function do_truename and do_falsename of the most derived class respectively. 3-4) Returns the string to be used as the representation of the boolean value true. Return value 1-2) The

Defined in header <tuple> const /*unspecified*/ ignore; (since C++11) An object of unspecified type such that any value can be assigned to it with no effect. Intended for use with std::tie when unpacking a std::tuple, as a placeholder for the arguments that are not used. Example unpack a pair returned by set.insert(), but only save the boolean. #include <iostream> #include <string> #include <set> #include <tuple> int main() { std::set<st

template< class... Args > iterator emplace( const_iterator pos, Args&&... args ); (since C++11) Inserts a new element into the container directly before pos. The element is constructed through std::allocator_traits::construct, which typically uses placement-new to construct the element in-place at a location provided by the container. The arguments args... are forwarded to the constructor as std::forward<Args>(args).... All iterators, including the past-the-end iter

iterator begin(); (since {std}) const_iterator begin() const; (since {std}) const_iterator cbegin() const; (since {std}) Returns an iterator to the first element of the container. If the container is empty, the returned iterator will be equal to end(). Parameters (none). Return value Iterator to the first element. Exceptions noexcept specification: noexcept Complexity Constant. Example See also end cend returns an iterator to the end (public member

reference back(); (since {std}) const_reference back() const; (since {std}) Returns reference to the last element in the container. Calling back on an empty container is undefined. Parameters (none). Return value Reference to the last element. Complexity Constant. Notes For a container c, the expression return c.back(); is equivalent to { auto tmp = c.end(); --tmp; return *tmp; } Example The following code uses back to display the last element of a std::dynarray<

std::string message() const; (since C++11) Returns an explanatory message for the stored error code and error category. Effectively calls category().message(value()). Parameters (none). Return value An explanatory message for the stored error code and error category. Exceptions (none).