A simple class for holding temporary references to a string literal or String. More...

Public Member Functions

 StringRef (const char *stringLiteral) noexcept
 Creates a StringRef from a raw string literal. More...
 
 StringRef (String::CharPointerType stringLiteral) noexcept
 Creates a StringRef from a raw char pointer. More...
 
 StringRef (const String &string) noexcept
 Creates a StringRef from a String. More...
 
 StringRef () noexcept
 Creates a StringRef pointer to an empty string. More...
 
 operator const String::CharPointerType::CharType * () const noexcept
 Returns a raw pointer to the underlying string data. More...
 
 operator String::CharPointerType () const noexcept
 Returns a pointer to the underlying string data as a char pointer object. More...
 
bool isEmpty () const noexcept
 Returns true if the string is empty. More...
 
bool isNotEmpty () const noexcept
 Returns true if the string is not empty. More...
 
int length () const noexcept
 Returns the number of characters in the string. More...
 
juce_wchar operator[] (int index) const noexcept
 Retrieves a character by index. More...
 
bool operator== (const String &s) const noexcept
 Compares this StringRef with a String. More...
 
bool operator!= (const String &s) const noexcept
 Compares this StringRef with a String. More...
 
bool operator== (StringRef s) const noexcept
 Case-sensitive comparison of two StringRefs. More...
 
bool operator!= (StringRef s) const noexcept
 Case-sensitive comparison of two StringRefs. More...
 

Public Attributes

String::CharPointerType text
 The text that is referenced. More...
 

Detailed Description

A simple class for holding temporary references to a string literal or String.

Unlike a real String object, the StringRef does not allocate any memory or take ownership of the strings you give to it - it simply holds a reference to a string that has been allocated elsewhere. The main purpose of the class is to be used instead of a const String& as the type of function arguments where the caller may pass either a string literal or a String object. This means that when the called uses a string literal, there's no need for an temporary String object to be allocated, and this cuts down overheads substantially.

Because the class is simply a wrapper around a pointer, you should always pass it by value, not by reference.

void myStringFunction1 (const String&);
void myStringFunction2 (StringRef);
myStringFunction1 ("abc"); // Implicitly allocates a temporary String object.
myStringFunction2 ("abc"); // Much faster, as no local allocations are needed.

For examples of it in use, see the XmlElement or StringArray classes.

Bear in mind that there are still many cases where it's better to use an argument which is a const String&. For example if the function stores the string or needs to internally create a String from the argument, then it's better for the original argument to already be a String.

See also
String

Constructor & Destructor Documentation

◆ StringRef() [1/4]

StringRef::StringRef ( const char *  stringLiteral)
noexcept

Creates a StringRef from a raw string literal.

The StringRef object does NOT take ownership or copy this data, so you must ensure that the data does not change during the lifetime of the StringRef. Note that this pointer cannot be null!

◆ StringRef() [2/4]

StringRef::StringRef ( String::CharPointerType  stringLiteral)
noexcept

Creates a StringRef from a raw char pointer.

The StringRef object does NOT take ownership or copy this data, so you must ensure that the data does not change during the lifetime of the StringRef.

◆ StringRef() [3/4]

StringRef::StringRef ( const String string)
noexcept

Creates a StringRef from a String.

The StringRef object does NOT take ownership or copy the data from the String, so you must ensure that the String is not modified or deleted during the lifetime of the StringRef.

◆ StringRef() [4/4]

StringRef::StringRef ( )
noexcept

Creates a StringRef pointer to an empty string.

Member Function Documentation

◆ operator const String::CharPointerType::CharType *()

StringRef::operator const String::CharPointerType::CharType * ( ) const
noexcept

Returns a raw pointer to the underlying string data.

◆ operator String::CharPointerType()

StringRef::operator String::CharPointerType ( ) const
noexcept

Returns a pointer to the underlying string data as a char pointer object.

◆ isEmpty()

bool StringRef::isEmpty ( ) const
noexcept

Returns true if the string is empty.

◆ isNotEmpty()

bool StringRef::isNotEmpty ( ) const
noexcept

Returns true if the string is not empty.

◆ length()

int StringRef::length ( ) const
noexcept

Returns the number of characters in the string.

◆ operator[]()

juce_wchar StringRef::operator[] ( int  index) const
noexcept

Retrieves a character by index.

◆ operator==() [1/2]

bool StringRef::operator== ( const String s) const
noexcept

Compares this StringRef with a String.

◆ operator!=() [1/2]

bool StringRef::operator!= ( const String s) const
noexcept

Compares this StringRef with a String.

◆ operator==() [2/2]

bool StringRef::operator== ( StringRef  s) const
noexcept

Case-sensitive comparison of two StringRefs.

◆ operator!=() [2/2]

bool StringRef::operator!= ( StringRef  s) const
noexcept

Case-sensitive comparison of two StringRefs.

Member Data Documentation

◆ text

String::CharPointerType StringRef::text

The text that is referenced.

Referenced by Rectangle< int >::fromString(), and operator+().


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