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 char8_t *str)
	Constructs from a NUL-terminated const char8_t * pointer.
	StringPiece (std::nullptr_t p)
	Constructs an empty StringPiece.
	StringPiece (const std::string &str)
	Constructs from a std::string.
	StringPiece (const std::u8string &str)
	Constructs from a std::u8string.
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 char8_t *str, int32_t len)
	Constructs from a const char8_t * 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	set (const char8_t *xdata, int32_t len)
	Resets the stringpiece to refer to new data.
void	set (const char8_t *str)
	Resets 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.
int32_t	find (StringPiece needle, int32_t offset)
	Searches the StringPiece for the given search string (needle);.
int32_t	compare (StringPiece other)
	Compares this StringPiece with the other StringPiece, with semantics similar to std::string::compare().
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 char8_t * str ) [inline]

Constructs from a NUL-terminated const char8_t * pointer.

Parameters:

str

a NUL-terminated const char8_t * pointer

Draft:: This API may be changed in the future versions and was introduced in ICU 67

Definition at line 85 of file stringpiece.h.

icu::StringPiece::StringPiece ( std::nullptr_t p ) [inline]

Constructs an empty StringPiece.

Needed for type disambiguation from multiple other overloads.

Parameters:

p

nullptr

Draft:: This API may be changed in the future versions and was introduced in ICU 67

Definition at line 93 of file stringpiece.h.

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

Constructs from a std::string.

Stable:: ICU 4.2

Definition at line 100 of file stringpiece.h.

icu::StringPiece::StringPiece ( const std::u8string & str ) [inline]

Constructs from a std::u8string.

Draft:: This API may be changed in the future versions and was introduced in ICU 67

Definition at line 108 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();  // or const char8_t*
     size_t size();
   };

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

Starting with C++20, data() may also return a const char8_t* pointer, as from std::u8string_view.

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 145 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 156 of file stringpiece.h.

icu::StringPiece::StringPiece	(	const char8_t *	str,
		int32_t	len
	)			`[inline]`

Constructs from a const char8_t * pointer and a specified length.

Parameters:

	str	a const char8_t * pointer (need not be terminated)
	len	the length of the string; must be non-negative

Draft:: This API may be changed in the future versions and was introduced in ICU 67

Definition at line 165 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 221 of file stringpiece.h.

int32_t icu::StringPiece::compare ( StringPiece other )

Compares this StringPiece with the other StringPiece, with semantics similar to std::string::compare().

Parameters:

other

The string to compare to.

Returns:: below zero if this < other; above zero if this > other; 0 if this == other.

Draft:: This API may be changed in the future versions and was introduced in ICU 67

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

Returns the string pointer.

May be nullptr 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 197 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 215 of file stringpiece.h.

int32_t icu::StringPiece::find	(	StringPiece	needle,
		int32_t	offset
	)

Searches the StringPiece for the given search string (needle);.

Parameters:

	needle	The string for which to search.
	offset	Where to start searching within this string (haystack).

Returns:: The offset of needle in haystack, or -1 if not found.

Draft:: This API may be changed in the future versions and was introduced in ICU 67

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 209 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 266 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 281 of file stringpiece.h.

void icu::StringPiece::set ( const char8_t * str ) [inline]

Resets the stringpiece to refer to new data.

Parameters:

str

a pointer to a NUL-terminated string.

Draft:: This API may be changed in the future versions and was introduced in ICU 67

Definition at line 255 of file stringpiece.h.

void icu::StringPiece::set	(	const char8_t *	xdata,
		int32_t	len
	)			`[inline]`

Resets 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

Draft:: This API may be changed in the future versions and was introduced in ICU 67

Definition at line 246 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 229 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 203 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 325 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 315 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