Section 3: library functions
std::strstreambuf::overflow – std::strstreambuf::overflow Synopsis protected: virtual int_type overflow(int_type c = EOF); Appends the character c to the put area of the buffer, reallocating if possible. 1) If c==EOF, does nothing 2) Otherwise, if the put area has a write position available (pptr() < epptr()), stores the character as if by *pptr()++ = c 3) Otherwise,…
std::strstreambuf::freeze – std::strstreambuf::freeze Synopsis void freeze(bool freezefl = true); If the buffer uses dynamic allocation, sets the frozen status of the stream to freezefl. While the stream is frozen, overflow() will not reallocate the buffer and the destructor will not deallocate the buffer (thereby causing a memory leak). Parameters freezefl – new value to set…
std::strstreambuf – std::strstreambuf Synopsis Defined in header <strstream> class strstreambuf : public std::basic_streambuf<char> (deprecated in C++98) std::strstreambuf is a std::basic_streambuf whose associated character sequence is a character array, which may be constant (e.g. a string literal), modifyable but not dynamic (e.g. a stack-allocated array), or dynamic, in which case the std::strstreambuf may be allowed to…
std::strstream::~strstream – std::strstream::~strstream Synopsis virtual ~strstream(); Destroys a std::strstream object, which also destroys the member std::strstreambuf, which may call the deallocation function if the underlying buffer was dynamically-allocated and not frozen. Parameters (none) Notes If str() was called on a dynamic strstream and freeze(false) was not called after that, this destructor leaks memory. Example //…
std::strstream::str – std::strstream::str Synopsis char *str(); Returns the pointer to the beginning of the buffer, after freezing it. Effectively calls rdbuf()->str() Notes Before a call to str() that uses the result as a C string, the stream buffer must be null-terminated. Regular output such as with stream << 1.2 does not store a null terminator,…
std::strstream::rdbuf – std::strstream::rdbuf Synopsis strstreambuf *rdbuf() const; Returns a pointer to the associated std::strstreambuf, casting away its constness (despite the const qualifier on the member function) Parameters (none) Return value Pointer to the associated std::strsteambuf, with constness cast away. Example // Run this code #include <strstream> int main() { const std::strstream buf; std::strstreambuf *ptr =…
std::strstream::pcount – std::strstream::pcount Synopsis int pcount() const; Returns the number of characters that were output in the put area of the associated std::strstreambuf. Effectively calls rdbuf()->pcount() Parameters (none) Return value The number of characters in the put area, or zero if nothing was output. Example // Run this code #include <strstream> #include <iostream> int main()…
std::strstream::freeze – std::strstream::freeze Synopsis void freeze(bool flag = true); If the stream is using a dynamically-allocated array for output, disables (flag == true) or enables (flag == false) automatic allocation/deallocation of the buffer. Effectively calls rdbuf()->freeze(flag) Notes After a call to str(), dynamic streams become frozen automatically. A call to freeze(false) is required before exiting…
std::strstream – std::strstream Synopsis Defined in header <strstream> class strstream : public std::iostream (deprecated in C++98) The class strstream implements input and output operations on array-backed streams. It essentially wraps a raw array I/O device implementation (std::strstreambuf) into the higher-level interface of std::basic_iostream. The typical implementation of strstream holds only one non-derived data member: an…
std::strstr – std::strstr Synopsis Defined in header<cstring> const char *strstr(const char *str, const char *target); char *strstr(char *str, const char *target); Finds the first occurrence of the byte string target in the byte string pointed to by str. The terminating null characters are not compared. Parameters str – pointer to the null-terminated byte string to…
std::strspn – std::strspn Synopsis Defined in header<cstring> size_t strspn(const char *dest, const char *src); Returns the length of the maximum initial segment (span) of the byte string pointed to by dest, that consists of only the characters found in byte string pointed to by src. Parameters dest – pointer to the null-terminated byte string to…
std::strrchr – std::strrchr Synopsis Defined in header<cstring> const char *strrchr(const char *str, int ch); char *strrchr(char *str, int ch); Finds the last occurrence of ch (after conversion to char) in the byte string pointed to by str. The terminating null character is considered to be a part of the string and can be found if…
std::strpbrk – std::strpbrk Synopsis Defined in header<cstring> const char *strpbrk(const char *dest, const char *breakset); char *strpbrk(char *dest, const char *breakset); Scans the null-terminated byte string pointed to by dest for any character from the null-terminated byte string pointed to by breakset, and returns a pointer to that character. Parameters dest – pointer to the…
std::strong_ordering – std::strong_ordering Synopsis Defined in header <compare> class strong_ordering; (since C++20) The class type std::strong_ordering is the result type of a three-way_comparison that * admits all six relational operators (==, !=, <, <=, >, >=) * implies substitutability: if a is equivalent to b, f(a) is also equivalent to f(b), where f denotes a…
std::strong_order – std::strong_order Synopsis Defined in header<compare> template <class T> (since C++ 20) constexpr std::strong_ordering strong_order(const T &a, const T &b); Compares two values using 3-way comparison and produces a result of type std::strong_ordering Specifically, * First, if std::numeric_limits<T>::is_iec559 is true, performs the ISO/IEC/IEEE 60559 totalOrder comparison of floating-point values and returns that result as…
std::strong_equality – std::strong_equality Synopsis Defined in header <compare> class strong_equality; (since C++20) The class type std::strong_equality is the result type of a three-way_comparison that * admits only equality and inequality comparisons (no less-than/greater-than) * implies substitutability: if a is equivalent to b, f(a) is also equivalent to f(b), where f denotes a function that reads…
std::strong_equal – std::strong_equal Synopsis Defined in header<compare> template <class T> (since C++ 20) constexpr std::strong_equality strong_equal(const T &a, const T &b); Compares two values using 3-way comparison and produces a result of type std::strong_equality Specifically, * If the expression a <=> b is well-formed and its result is convertible to std::strong_equality, returns that result. *…
std::strncpy – std::strncpy Synopsis Defined in header<cstring> char *strncpy(char *dest, const char *src, std::size_t count); Copies at most count characters of the byte string pointed to by src (including the terminating null character) to character array pointed to by dest. If count is reached before the entire string src was copied, the resulting character array…
std::strncmp – std::strncmp Synopsis Defined in header<cstring> int strncmp(const char *lhs, const char *rhs, size_t count); Compares at most count characters of two null-terminated byte strings. The comparison is done lexicographically. The sign of the result is the sign of the difference between the values of the first pair of characters (both interpreted as unsigned…
std::strncat – std::strncat Synopsis Defined in header<cstring> char *strncat(char *dest, const char *src, std::size_t count); Appends a byte string pointed to by src to a byte string pointed to by dest. At most count characters are copied. The resulting byte string is null-terminated. The destination byte string must have enough space for the contents of…