streams.primitives

A collection of compile-time functions to help in identifying stream types and related flavors of them.

Streams come in two main flavors: input and output streams.

Input streams are defined by the presence of a read function:

StreamResult readFromStream(DataType[] buffer)

Output streams are defined by the presence of a write function:

StreamResult writeToStream(DataType[] buffer)

Usually these functions can be used as Template Constraints when defining your own functions and symbols to work with streams.

void useBytes(S)(S stream) if (isInputStream!(S, ubyte)) {
    ubyte[8192] buffer;
    StreamResult result = stream.readFromStream(buffer);
    if (!result.hasError) {
      // Do something with the data.
    }
}

Members

Aliases

OptionalStreamError alias OptionalStreamError = Optional!StreamError: A convenience alias for an optional stream error, which is a common return type for many stream methods.
StreamResult alias StreamResult = Either!(uint, "count", StreamError, "error"): Either a number of items that have been read or written, or a stream error, as a common result type for many stream operations.

Functions

isByteInputStream bool isByteInputStream(): Determines if the given stream type is an input stream for ubyte elements.
isByteOutputStream bool isByteOutputStream(): Determines if the given stream type is an output stream for ubyte elements.
isClosableStream bool isClosableStream(): Determines if the given template argument is a closable stream type, which defines a Optional!StreamError closeStream() method as a means to close and/or deallocate the underlying resource that the stream reads from or writes to.
isFlushableStream bool isFlushableStream(): Determines if the given template argument is a flushable stream type, which is any output stream that defines a Optional!StreamError flushStream() method, which should cause any data buffered by the stream or its resources to be flushed. The exact nature of how a flush operates is implementation- dependent.
isInputStream bool isInputStream(): Determines if the given stream type is an input stream for reading data of the given type.
isNonPointerStream bool isNonPointerStream(): Determines if the given template argument is a direct stream type, and that it is not a pointer. If true, then this implies that the caller "owns" the stream, and the stream should not be used outside of owner's scope.
isOutputStream bool isOutputStream(): Determines if the given stream type is an output stream for writing data of the given type.
isPointerToStream bool isPointerToStream(): Determines if the given template argument is a pointer to a stream.
isSeekableStream bool isSeekableStream(): Determines if the given template argument is a seekable stream type, which is any stream, input or output, that defines a Optional!StreamError seekInStream(ulong offset) function for seeking to a particular position in a stream, specified by the offset in terms of elements.
isSomeInputStream bool isSomeInputStream(): Determines if the given template argument is some form of input stream.
isSomeOutputStream bool isSomeOutputStream(): Determines if the given template argument is some form of output stream.
isSomeStream bool isSomeStream(): Determines if the given template argument is a stream of any kind; that is, it is at least implementing the functions required to be an input or output stream.
isSomeStream bool isSomeStream(): Determines if the given stream type is an input or output stream for data of the given type.

Structs

ErrorInputStream struct ErrorInputStream(T): An input stream that always returns an error response.
ErrorOutputStream struct ErrorOutputStream(T): An output stream that always returns an error response.
NoOpInputStream struct NoOpInputStream(T): An input stream that always reads 0 elements.
NoOpOutputStream struct NoOpOutputStream(T): An output stream that always writes 0 elements.
StreamError struct StreamError: An error that occurred during a stream operation, which includes a short message, as well as an integer code which is usually the last stream operation return code.

Templates

StreamType template StreamType(S): A template that evaluates to the type of a given input or output stream.