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Version: 3.2.6 |
#include <wx/buffer.h>
Inheritance diagram for wxScopedCharTypeBuffer< T >:Detailed Description
template<typename T>
class wxScopedCharTypeBuffer< T >
wxScopedCharTypeBuffer<T> is a template class for storing characters.
Data are stored in reference-counted buffer. In other words, making a copy of wxScopedCharTypeBuffer<T> will not make another copy of the stored string data, it will still point to the same location in memory.
wxScopedCharTypeBuffer<T> supports two storage modes: owned and non-owned. "Owned" data buffer (created with CreateOwned() or wxCharTypeBuffer<T> derived class) owns the data and frees them when the last buffer pointing to them is destroyed.
"Non-owned" buffer (created with CreateNonOwned()), on the other hand, references data owned by somebody else – typical use is by wxString::mb_str() or wxString::wc_str(), which may return non-owned buffer pointing to wxString's internal store.
Because of this, the validity of data stored in wxScopedCharTypeBuffer<T> is limited by the lifetime of the "parent" object that created the buffer (e.g. the wxString on which mb_str() was called).
If you need to preserve the data for longer, assign it to wxCharTypeBuffer<T> instead of wxScopedCharTypeBuffer<T>. On the other hand, use wxScopedCharTypeBuffer<T> if the buffer is to be destroyed before the "parent" object – typical use would be creating it on the stack and destroying when it goes out of scope (hence the class' name).
- Template Parameters
-
T The type of the characters stored in this class.
- Since
- 2.9.0
Public Types | |
| typedef T | CharType |
| Stored characters type. More... | |
Public Member Functions | |
| wxScopedCharTypeBuffer () | |
| Default constructor, creates NULL buffer. More... | |
| wxScopedCharTypeBuffer (const wxScopedCharTypeBuffer &src) | |
| Copy constructor. More... | |
| wxScopedCharTypeBuffer & | operator= (const wxScopedCharTypeBuffer &src) |
| Assignment operator behaves in the same way as the copy constructor. More... | |
| ~wxScopedCharTypeBuffer () | |
| Destructor. More... | |
| CharType * | release () const |
| Returns the internal pointer and resets the buffer. More... | |
| void | reset () |
| Resets the buffer to NULL, freeing the data if necessary. More... | |
| CharType * | data () |
| Returns pointer to the stored data. More... | |
| const CharType * | data () const |
| Returns const pointer to the stored data. More... | |
| size_t | length () const |
| Returns length of the string stored. More... | |
| operator const CharType * () const | |
| Implicit conversion to C string. More... | |
| CharType | operator[] (size_t n) const |
| Random access to the stored C string. More... | |
Static Public Member Functions | |
| static const wxScopedCharTypeBuffer | CreateNonOwned (const CharType *str, size_t len=wxNO_LEN) |
| Creates non-owned buffer from string data str. More... | |
| static const wxScopedCharTypeBuffer | CreateOwned (CharType *str, size_t len=wxNO_LEN) |
| Creates owned buffer from str and takes ownership of it. More... | |
Member Typedef Documentation
◆ CharType
| typedef T wxScopedCharTypeBuffer< T >::CharType |
Stored characters type.
Constructor & Destructor Documentation
◆ wxScopedCharTypeBuffer() [1/2]
| wxScopedCharTypeBuffer< T >::wxScopedCharTypeBuffer | ( | ) |
Default constructor, creates NULL buffer.
◆ wxScopedCharTypeBuffer() [2/2]
| wxScopedCharTypeBuffer< T >::wxScopedCharTypeBuffer | ( | const wxScopedCharTypeBuffer< T > & | src | ) |
Copy constructor.
Increases reference count on the data, does not make wxStrdup() copy of the data.
◆ ~wxScopedCharTypeBuffer()
| wxScopedCharTypeBuffer< T >::~wxScopedCharTypeBuffer | ( | ) |
Destructor.
Frees stored data if it is in "owned" mode and data's reference count reaches zero.
Member Function Documentation
◆ CreateNonOwned()
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static |
Creates non-owned buffer from string data str.
The buffer's destructor will not destroy str. The returned buffer's data is valid only as long as str is valid.
- Parameters
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str String data. len If specified, length of the string, otherwise the string is considered to be NUL-terminated.
◆ CreateOwned()
|
static |
Creates owned buffer from str and takes ownership of it.
The buffer's destructor will free str when its reference count reaches zero (initial count is 1).
- Parameters
-
str String data. len If specified, length of the string, otherwise the string is considered to be NUL-terminated.
◆ data() [1/2]
| CharType* wxScopedCharTypeBuffer< T >::data | ( | ) |
Returns pointer to the stored data.
◆ data() [2/2]
| const CharType* wxScopedCharTypeBuffer< T >::data | ( | ) | const |
Returns const pointer to the stored data.
◆ length()
| size_t wxScopedCharTypeBuffer< T >::length | ( | ) | const |
Returns length of the string stored.
◆ operator const CharType *()
| wxScopedCharTypeBuffer< T >::operator const CharType * | ( | ) | const |
Implicit conversion to C string.
◆ operator=()
| wxScopedCharTypeBuffer& wxScopedCharTypeBuffer< T >::operator= | ( | const wxScopedCharTypeBuffer< T > & | src | ) |
Assignment operator behaves in the same way as the copy constructor.
◆ operator[]()
| CharType wxScopedCharTypeBuffer< T >::operator[] | ( | size_t | n | ) | const |
Random access to the stored C string.
◆ release()
| CharType* wxScopedCharTypeBuffer< T >::release | ( | ) | const |
Returns the internal pointer and resets the buffer.
It's the caller responsibility to deallocate the returned pointer using free() function.
Notice that this method is dangerous because it can only be called on a non-shared owning buffer. Calling it on any other kind of buffer object will result in a crash after the pointer is freed, so avoid using it unless absolutely necessary and you are absolutely certain that the buffer is not shared.
◆ reset()
| void wxScopedCharTypeBuffer< T >::reset | ( | ) |
Resets the buffer to NULL, freeing the data if necessary.