API Reference — trio/Stream

AccessMode

Alias, scoped under BoundedIOStream, for trio::AccessMode — controls whether a stream is opened for reading or writing.

Why this exists

BoundedIOStream::AccessMode re-exports trio::AccessMode so code working with BoundedIOStream (and its subclasses like FileStream) can refer to the access-mode type through the stream type itself, without an extra trio:: qualification.

Relationships

  • trio::AccessMode — the underlying type this alias re-exports
  • FileStream::create — consumer that takes an AccessMode argument

class TRIOAPI BoundedIOStream : public Controllable, public Readable, public Writable, public Seekable, public Bounded

Base interface for a fully-featured, finite-size I/O stream — one type that can be opened/closed, read, written, seeked, and sized.

When to use this

Depend on BoundedIOStream when code needs the full set of stream capabilities (control, read, write, seek, size) rather than composing the individual trio::Concepts interfaces by hand. FileStream is the concrete implementation used for on-disk files.

Method groups

Group Methods
lifecycle (inherited from Controllable: open, close)
io (inherited from Readable/Writable: read, write)
position (inherited from Seekable: tell, seek)
size (inherited from Bounded: size)

Example

trio::BoundedIOStream* stream = /* obtained from a concrete implementation */;
stream->open();
std::uint64_t total = stream->size();
stream->close();

Constraints

  • Exposes static sc::StatusCode members (OpenError, ReadError, WriteError, AlreadyOpenError, SeekError) for reporting stream-level failures.

Watch out for

  • AlreadyOpenError and OpenError are separate status codes. Checking only OpenError after a failed open will miss the case where the stream was opened twice. Test status == BoundedIOStream::AlreadyOpenError explicitly if double-open is a plausible caller error.

OpenMode

Alias, scoped under BoundedIOStream, for trio::OpenMode — controls whether a stream is opened in binary or textual mode.

Why this exists

BoundedIOStream::OpenMode re-exports trio::OpenMode for the same reason as AccessMode: so it can be referenced via the stream type itself.

Relationships

  • trio::OpenMode — the underlying type this alias re-exports
  • FileStream::create — consumer that takes an OpenMode argument