Defined in header <cctype> int isblank( int ch ); (since C++11) Checks if the given character is a blank character as classified by the currently installed C locale. Blank characters are whitespace characters used to separate words within a sentence. In the default C locale, only space (0x20) and horizontal tab (0x09) are classified as blank characters. The behavior is undefined if the value of ch is not representable as unsigned char and is not equal to EOF. Parameters

Defined in header <bitset> template< std::size_t N > class bitset; The class template bitset represents a fixed-size sequence of N bits. Bitsets can be manipulated by standard logic operators and converted to and from strings and integers. bitset meets the requirements of CopyConstructible and CopyAssignable. Template parameters N - the number of bits to allocate storage for Member types reference proxy class representing a reference to a bit (class)

Defined in header <cstdio> std::FILE* fopen( const char* filename, const char* mode ); Opens a file indicated by filename and returns a file stream associated with that file. mode is used to determine the file access mode. Parameters filename - file name to associate the file stream to mode - null-terminated character string determining file access mode File access mode string Meaning Explanation Action if file already exists Action if file does not

Defined in header <random> template< class RealType = double > class normal_distribution; (since C++11) Generates random numbers according to the Normal (or Gaussian) random number distribution. It is defined as: f(x; μ,σ) = 1σ√2π exp⎛⎜⎝- 12 ⎛⎜⎝ x-μσ ⎞⎟⎠2⎞⎟⎠ Here μ is the mean and σ is the standard deviation (stddev). std::normal_distribution satisfies all requirements of RandomNumberDistribution. Template parameters RealType - The result type genera

Defined in header <cmath> float hypot( float x, float y ); (1) (since C++11) double hypot( double x, double y ); (2) (since C++11) long double hypot( long double x, long double y ); (3) (since C++11) Promoted hypot( Arithmetic1 x, Arithmetic2 y ); (4) (since C++11) 1-3) Computes the square root of the sum of the squares of x and y, without undue overflow or underflow at intermediate stages of the computation. 4) A set of overloads or a func

Defined in header <complex> template< class T > complex<T> sqrt( const complex<T>& z ); Computes the square root of the complex number z with a branch cut along the negative real axis. Parameters z - complex number to take the square root of Return value If no errors occur, returns the square root of z, in the range of the right half-plane, including the imaginary axis ([0; +∞) along the real axis and (−∞; +∞) along the imaginary axis.).

Defined in header <ios> class ios_base; The class ios_base is a multipurpose class that serves as the base class for all I/O stream classes. It maintains several kinds of data: 1) state information: stream status flags 2) control information: flags that control formatting of both input and output sequences and the imbued locale 3) private storage: indexed extensible data structure that allows both long and void* members, which may be implemented as two arbitrary-length a

T& operator[]( const Key& key ); (1) (since C++11) T& operator[]( Key&& key ); (2) (since C++11) Returns a reference to the value that is mapped to a key equivalent to key, performing an insertion if such key does not already exist. 1) Inserts a value_type object constructed in-place from std::piecewise_construct, std::forward_as_tuple(key), std::tuple<>() if the key does not exist. This function is equivalent to return this->try_emplace(key).first-&

"Substitution Failure Is Not An Error" This rule applies during overload resolution of function templates: When substituting the deduced type for the template parameter fails, the specialization is discarded from the overload set instead of causing a compile error. This feature is used in template metaprogramming. Explanation Function template parameters are substituted (replaced by template arguments) twice: explicitly specified template arguments are substituted before template argument

In a member-specification of a class/struct or union, define the visibility of subsequent members. In a base-clause of a derived class declaration, define the accessibility of inherited members of the subsequent base-specifiers. Syntax public : member-declarations (1) protected : member-declarations (2) private : member-declarations (3) class_name : public base_classes (4) class_name : protected base_classes (5) class_name : private base_classes (6) 1)