icu::StringPiece Class Reference

A string-like object that points to a sized piece of memory. More...

#include <stringpiece.h>

Inheritance diagram for icu::StringPiece:

Public Member Functions
	StringPiece ()
	Default constructor, creates an empty StringPiece.
	StringPiece (const char *str)
	Constructs from a NUL-terminated const char * pointer.
	StringPiece (const std::string &str)
	Constructs from a std::string.
template<typename T , typename = typename std::enable_if< std::is_same<decltype(T().data()), const char*>::value && std::is_same<decltype(T().size()), size_t>::value>::type>
	StringPiece (T str)
	Constructs from some other implementation of a string piece class, from any C++ record type that has these two methods:.
	StringPiece (const char *offset, int32_t len)
	Constructs from a const char * pointer and a specified length.
	StringPiece (const StringPiece &x, int32_t pos)
	Substring of another StringPiece.
	StringPiece (const StringPiece &x, int32_t pos, int32_t len)
	Substring of another StringPiece.
const char *	data () const
	Returns the string pointer.
int32_t	size () const
	Returns the string length.
int32_t	length () const
	Returns the string length.
UBool	empty () const
	Returns whether the string is empty.
void	clear ()
	Sets to an empty string.
void	set (const char *xdata, int32_t len)
	Reset the stringpiece to refer to new data.
void	set (const char *str)
	Reset the stringpiece to refer to new data.
void	remove_prefix (int32_t n)
	Removes the first n string units.
void	remove_suffix (int32_t n)
	Removes the last n string units.
StringPiece	substr (int32_t pos, int32_t len=npos) const
	Returns a substring of this StringPiece.
Static Public Attributes
static const int32_t	npos
	Maximum integer, used as a default value for substring methods.

Detailed Description

A string-like object that points to a sized piece of memory.

We provide non-explicit singleton constructors so users can pass in a "const char*" or a "string" wherever a "StringPiece" is expected.

Functions or methods may use StringPiece parameters to accept either a "const char*" or a "string" value that will be implicitly converted to a StringPiece.

Systematic usage of StringPiece is encouraged as it will reduce unnecessary conversions from "const char*" to "string" and back again.

Stable:: ICU 4.2

Definition at line 60 of file stringpiece.h.

Constructor & Destructor Documentation

icu::StringPiece::StringPiece ( ) [inline]

Default constructor, creates an empty StringPiece.

Stable:: ICU 4.2

Definition at line 70 of file stringpiece.h.

icu::StringPiece::StringPiece ( const char * str )

Constructs from a NUL-terminated const char * pointer.

Parameters:

str

a NUL-terminated const char * pointer

Stable:: ICU 4.2

icu::StringPiece::StringPiece ( const std::string & str ) [inline]

Constructs from a std::string.

Stable:: ICU 4.2

Definition at line 81 of file stringpiece.h.

template<typename T , typename = typename std::enable_if< std::is_same<decltype(T().data()), const char*>::value && std::is_same<decltype(T().size()), size_t>::value>::type>

icu::StringPiece::StringPiece ( T str ) [inline]

Constructs from some other implementation of a string piece class, from any C++ record type that has these two methods:.

 {.cpp}

   struct OtherStringPieceClass {
     const char* data();
     size_t size();
   };

The other string piece class will typically be std::string_view from C++17 or absl::string_view from Abseil.

Parameters:

str

the other string piece

Draft:: This API may be changed in the future versions and was introduced in ICU 65

Definition at line 107 of file stringpiece.h.

icu::StringPiece::StringPiece	(	const char *	offset,
		int32_t	len
	)			`[inline]`

Constructs from a const char * pointer and a specified length.

Parameters:

	offset	a const char * pointer (need not be terminated)
	len	the length of the string; must be non-negative

Stable:: ICU 4.2

Definition at line 116 of file stringpiece.h.

icu::StringPiece::StringPiece	(	const StringPiece &	x,
		int32_t	pos
	)

Substring of another StringPiece.

Parameters:

	x	the other StringPiece
	pos	start position in x; must be non-negative and <= x.length().

Stable:: ICU 4.2

icu::StringPiece::StringPiece	(	const StringPiece &	x,
		int32_t	pos,
		int32_t	len
	)

Substring of another StringPiece.

Parameters:

	x	the other StringPiece
	pos	start position in x; must be non-negative and <= x.length().
	len	length of the substring; must be non-negative and will be pinned to at most x.length() - pos.

Stable:: ICU 4.2

Member Function Documentation

void icu::StringPiece::clear ( ) [inline]

Sets to an empty string.

Stable:: ICU 4.2

Definition at line 168 of file stringpiece.h.

References NULL.

const char* icu::StringPiece::data ( ) const [inline]

Returns the string pointer.

May be NULL if it is empty.

data() may return a pointer to a buffer with embedded NULs, and the returned buffer may or may not be null terminated. Therefore it is typically a mistake to pass data() to a routine that expects a NUL terminated string.

Returns:: the string pointer

Stable:: ICU 4.2

Definition at line 144 of file stringpiece.h.

UBool icu::StringPiece::empty ( ) const [inline]

Returns whether the string is empty.

Returns:: TRUE if the string is empty

Stable:: ICU 4.2

Definition at line 162 of file stringpiece.h.

int32_t icu::StringPiece::length ( void ) const [inline]

Returns the string length.

Same as size().

Returns:: the string length

Stable:: ICU 4.2

Definition at line 156 of file stringpiece.h.

void icu::StringPiece::remove_prefix ( int32_t n ) [inline]

Removes the first n string units.

Parameters:

n

prefix length, must be non-negative and <=length()

Stable:: ICU 4.2

Definition at line 190 of file stringpiece.h.

void icu::StringPiece::remove_suffix ( int32_t n ) [inline]

Removes the last n string units.

Parameters:

n

suffix length, must be non-negative and <=length()

Stable:: ICU 4.2

Definition at line 205 of file stringpiece.h.

void icu::StringPiece::set ( const char * str )

Reset the stringpiece to refer to new data.

Parameters:

str

a pointer to a NUL-terminated string.

Stable:: ICU 4.8

void icu::StringPiece::set	(	const char *	xdata,
		int32_t	len
	)			`[inline]`

Reset the stringpiece to refer to new data.

Parameters:

	xdata	pointer the new string data. Need not be nul terminated.
	len	the length of the new data

Stable:: ICU 4.8

Definition at line 176 of file stringpiece.h.

int32_t icu::StringPiece::size ( ) const [inline]

Returns the string length.

Same as length().

Returns:: the string length

Stable:: ICU 4.2

Definition at line 150 of file stringpiece.h.

StringPiece icu::StringPiece::substr	(	int32_t	pos,
		int32_t	len = `npos`
	)			const `[inline]`

Returns a substring of this StringPiece.

Parameters:

	pos	start position; must be non-negative and <= length().
	len	length of the substring; must be non-negative and will be pinned to at most length() - pos.

Returns:: the substring StringPiece

Stable:: ICU 4.2

Definition at line 229 of file stringpiece.h.

Field Documentation

const int32_t icu::StringPiece::npos [static]

Maximum integer, used as a default value for substring methods.

Stable:: ICU 4.2

Definition at line 219 of file stringpiece.h.

The documentation for this class was generated from the following file:

stringpiece.h

icu::StringPiece Class Reference

Public Member Functions

Static Public Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Field Documentation