cxx::String Class Reference

Allocation free string class with explicit length field. More...

#include <string>

Inheritance diagram for cxx::String:

Collaboration diagram for cxx::String:

Public Types
typedef char const *	Index
	Character index type.

Public Member Functions
	String (char const *s) noexcept
	Initialize from a zero-terminated string.
	String (char const *s, unsigned long len) noexcept
	Initialize from a pointer to first character and a length.
	String (char const *s, char const *e) noexcept
	Initialize with start and end pointer.
	String ()
	Zero-initialize. Create an invalid string.
Index	start () const
	Pointer to first character.
Index	end () const
	Pointer to first byte behind the string.
int	len () const
	Length.
void	start (char const *s)
	Set start.
void	len (unsigned long len)
	Set length.
bool	empty () const
	Check if the string has length zero.
String	head (Index end) const
	Return prefix up to index.
String	head (unsigned long end) const
	Prefix of length end.
String	substr (unsigned long idx, unsigned long len=~0UL) const
	Substring of length len starting at idx.
String	substr (char const *start, unsigned long len=0) const
	Substring of length len starting at start.
template<typename F>
char const *	find_match (F &&match) const
	Find matching character. match should be a function such as isspace.
char const *	find (char const *c) const
	Find character. Return end() if not found.
char const *	find (int c) const
	Find character. Return end() if not found.
char const *	rfind (char const *c) const
	Find right-most character. Return end() if not found.
Index	starts_with (cxx::String const &c) const
	Check if c is a prefix of string.
char const *	find (int c, char const *s) const
	Find character c starting at position s. Return end() if not found.
char const *	find (char const *c, char const *s) const
	Find character set at position.
char const &	operator[] (unsigned long idx) const
	Get character at idx.
char const &	operator[] (int idx) const
	Get character at idx.
char const &	operator[] (Index idx) const
	Get character at idx.
bool	eof (char const *s) const
	Check if pointer s points behind string.
template<typename INT>
int	from_dec (INT *v) const
	Convert decimal string to integer.
template<typename INT>
int	from_hex (INT *v) const
	Convert hex string to integer.
template<typename INT>
int	from_number (INT *v, unsigned base=0) const
	Convert a number string to an integer.
bool	operator== (String const &o) const
	Equality.
bool	operator!= (String const &o) const
	Inequality.

Detailed Description

Allocation free string class with explicit length field.

This class is used to group characters of a string which belong to one syntactical token types number, identifier, string, whitespace or another single character.

Strings in this class can contain null bytes and may denote parts of other strings.

Examples

tmpfs/lib/src/fs.cc.

Definition at line 32 of file string.

Constructor & Destructor Documentation

String()

cxx::String::String ( char const * s, char const * e )

inlinenoexcept

Initialize with start and end pointer.

Parameters

s	first character of the string
e	pointer to first byte behind the string

Definition at line 50 of file string.

Member Function Documentation

find()

char const * cxx::String::find ( char const * c, char const * s ) const

inline

Find character set at position.

Parameters

c	zero-terminated string of characters to search for
s	start position of search in string

Return values

end()	if no char in c is contained in string at or behind s.
position	in string of some character in c.

Definition at line 193 of file string.

References end(), and eof().

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from_dec()

template<typename INT>

int cxx::String::from_dec ( INT * v ) const

inline

Convert decimal string to integer.

Template Parameters

INT	result integer type

Parameters

[out]

v

conversion result

Returns

position of first character not converted.

Definition at line 230 of file string.

References eof(), and start().

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from_hex()

template<typename INT>

int cxx::String::from_hex ( INT * v ) const

inline

Convert hex string to integer.

Template Parameters

INT	result integer type

Parameters

[out]

v

conversion result

Return values

-1	if the maximal amount of digits fitting into INT have been read,
position	of first character not converted otherwise.

Definition at line 259 of file string.

References eof(), and start().

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from_number()

template<typename INT>

int cxx::String::from_number ( INT * v, unsigned base = 0 ) const

inline

Convert a number string to an integer.

Converts the initial part of the string to a number, according to the given base. The string may start with an arbitrary amount of white space followed by a single optional + or - sign. If base is zero or 16, the string may then include a "0x" or "0X" prefix, and the number will be read in base 16; otherwise, a zero base is taken as 10 (decimal) unless the next character is '0', in which case it is taken as 8 (octal).

Conversion stops at the first character that is not a valid digit for the chosen base. If the string does not contain any digit at all, zero is returned and v is left unmodified.

Template Parameters

INT	result integer type

Parameters

[out]	v	conversion result
	base	Base of the number (0, 2..36)

Return values

>0	Success. Position of first character after the number.
0	The string does not contain a number.
-L4_EINVAL	Invalid base parameter
-L4_ERANGE	Parsed number too large to be stored in v

Definition at line 309 of file string.

References eof(), L4_EINVAL, L4_ERANGE, and start().

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starts_with()

Index cxx::String::starts_with ( cxx::String const & c ) const

inline

Check if c is a prefix of string.

Returns

0 if c is not a prefix, if it is a prefix, return first position not in c (which might be end()).

Definition at line 157 of file string.

References start().

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

• l4/cxx/string