[#BloombergLP-bdls-FdStreamBuf-setbuf] = xref:BloombergLP.adoc[BloombergLP]::xref:BloombergLP/bdls.adoc[bdls]::xref:BloombergLP/bdls/FdStreamBuf.adoc[FdStreamBuf]::setbuf :relfileprefix: ../../../ :mrdocs: Use the specified `buffer` of the specified `numBytes` capacity as the input/output buffer for this `streambuf`. If `buffer == 0`, the buffer is dynamically allocated with a default size. If both `buffer` and `numBytes` are zero a 1‐byte buffer is dynamically allocated. The behavior is undefined if any I/O has preceded this call, and unless the buffer is uninitialized before this call. == Synopsis Declared in `<bdls_fdstreambuf.h>` [source,cpp,subs="verbatim,replacements,macros,-callouts"] ---- virtual xref:BloombergLP/bdls/FdStreamBuf.adoc[FdStreamBuf]* setbuf( char_type* buffer, std::streamsize numBytes) override; ---- [.small]#Created with https://www.mrdocs.com[MrDocs]#