cpp/io/basic ios/rdbuf

Manages the associated stream buffer.

@1@ Returns the associated stream buffer. If there is no associated stream buffer, returns a null pointer.

@2@ Sets the associated stream buffer to. The error state is cleared by calling clear. Returns the associated stream buffer before the operation. If there is no associated stream buffer, returns a null pointer.

Return value
The associated stream buffer, or a null pointer if there was no associated stream buffer.