rapidjson::GenericStringRef< CharType > 模板结构体 参考

Reference to a constant string (not taking a copy) 更多...

#include <document.h>

Public 类型
typedef CharType	Ch
	character type of the string

Public 成员函数
template<SizeType N>
	GenericStringRef (const CharType(&str)[N]) RAPIDJSON_NOEXCEPT
	Create string reference from const character array
	GenericStringRef (const CharType *str)
	Explicitly create string reference from const character pointer
	GenericStringRef (const CharType *str, SizeType len)
	Create constant string reference from pointer and length
	GenericStringRef (const GenericStringRef &rhs)
	operator const Ch * () const
	implicit conversion to plain CharType pointer

Public 属性
const Ch *const	s
	plain CharType pointer
const SizeType	length
	length of the string (excluding the trailing NULL terminator)

相关符号
(注意: 这些不是成员符号.)
template<typename CharType>
GenericStringRef< CharType >	StringRef (const CharType *str)
	Mark a character pointer as constant string
template<typename CharType>
GenericStringRef< CharType >	StringRef (const CharType *str, size_t length)
	Mark a character pointer as constant string

详细描述

template<typename CharType>
struct rapidjson::GenericStringRef< CharType >

Reference to a constant string (not taking a copy)

模板参数

CharType

character type of the string

This helper class is used to automatically infer constant string references for string literals, especially from const (!) character arrays.

The main use is for creating JSON string values without copying the source string via an 分配器. This requires that the referenced string pointers have a sufficient lifetime, which exceeds the lifetime of the associated GenericValue.

Example

Value v("foo");   // ok, no need to copy & calculate length
const char foo[] = "foo";
v.SetString(foo); // ok
 
const char* bar = foo;
// Value x(bar); // not ok, can't rely on bar's lifetime
Value x(StringRef(bar)); // lifetime explicitly guaranteed by user
Value y(StringRef(bar, 3));  // ok, explicitly pass length

参见

StringRef, GenericValue::SetString

构造及析构函数说明

GenericStringRef() [1/3]

template<typename CharType>

template<SizeType N>

rapidjson::GenericStringRef< CharType >::GenericStringRef ( const CharType(&) str[N] )

inline

Create string reference from const character array

This constructor implicitly creates a constant string reference from a const character array. It has better performance than StringRef(const CharType*) by inferring the string length from the array length, and also supports strings containing null characters.

模板参数

N	length of the string, automatically inferred

参数

str	Constant character array, lifetime assumed to be longer than the use of the string in e.g. a GenericValue

后置条件

s == str

注解

Constant complexity.

There is a hidden, private overload to disallow references to non-const character arrays to be created via this constructor. By this, e.g. function-scope arrays used to be filled via snprintf are excluded from consideration. In such cases, the referenced string should be copied to the GenericValue instead.

GenericStringRef() [2/3]

template<typename CharType>

rapidjson::GenericStringRef< CharType >::GenericStringRef ( const CharType * str )

inlineexplicit

Explicitly create string reference from const character pointer

This constructor can be used to explicitly create a reference to a constant string pointer.

参见

StringRef(const CharType*)

参数

str	Constant character pointer, lifetime assumed to be longer than the use of the string in e.g. a GenericValue

后置条件

s == str

注解

There is a hidden, private overload to disallow references to non-const character arrays to be created via this constructor. By this, e.g. function-scope arrays used to be filled via snprintf are excluded from consideration. In such cases, the referenced string should be copied to the GenericValue instead.

GenericStringRef() [3/3]

template<typename CharType>

rapidjson::GenericStringRef< CharType >::GenericStringRef ( const CharType * str, SizeType len )

inline

Create constant string reference from pointer and length

参数

str	constant string, lifetime assumed to be longer than the use of the string in e.g. a GenericValue
len	length of the string, excluding the trailing NULL terminator

后置条件

s == str && length == len

注解

Constant complexity.

友元及相关符号说明

StringRef() [1/2]

template<typename CharType>

GenericStringRef< CharType > StringRef ( const CharType * str )

related

Mark a character pointer as constant string

Mark a plain character pointer as a "string literal". This function can be used to avoid copying a character string to be referenced as a value in a JSON GenericValue object, if the string's lifetime is known to be valid long enough.

模板参数

CharType

Character type of the string

参数

str	Constant string, lifetime assumed to be longer than the use of the string in e.g. a GenericValue

返回

GenericStringRef string reference object

参见

GenericValue::GenericValue(StringRefType), GenericValue::operator=(StringRefType), GenericValue::SetString(StringRefType), GenericValue::PushBack(StringRefType, Allocator&), GenericValue::AddMember

StringRef() [2/2]

template<typename CharType>

GenericStringRef< CharType > StringRef ( const CharType * str, size_t length )

related

Mark a character pointer as constant string

Mark a plain character pointer as a "string literal". This function can be used to avoid copying a character string to be referenced as a value in a JSON GenericValue object, if the string's lifetime is known to be valid long enough.

This version has better performance with supplied length, and also supports string containing null characters.

模板参数

CharType

character type of the string

参数

str	Constant string, lifetime assumed to be longer than the use of the string in e.g. a GenericValue
length	The length of source string.

返回

GenericStringRef string reference object

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该结构体的文档由以下文件生成:

• include/rapidjson/document.h