Describes a fixed-length, copy-on-write, type-erased tuple with elements of any type. More...

#include <message.hpp>

Classes
struct	cli_arg
	Stores the name of a command line option ("<long name>[,<short name>]") along with a description and a callback. More...

struct	cli_res
	Stores the result of `message::extract_opts`. More...

Public Types
using	help_factory = std::function< std::string(const std::vector< cli_arg > &)>

Public Member Functions
	message ()=default
	Creates an empty message.

	message (message &&)
	Move constructor.

	message (const message &)=default
	Copy constructor.

message &	operator= (message &&)
	Move assignment.

message &	operator= (const message &)=default
	Copy assignment.

size_t	size () const
	Returns the size of this message.

message	drop (size_t n) const
	Creates a new message with all but the first n values.

message	drop_right (size_t n) const
	Creates a new message with all but the last n values.

message	take (size_t n) const
	Creates a new message from the first n values.

message	take_right (size_t n) const
	Creates a new message from the last n values.

message	slice (size_t p, size_t n) const
	Creates a new message of size `n` starting at the element at position `p`.

void *	mutable_at (size_t p)
	Returns a mutable pointer to the element at position `p`.

const void *	at (size_t p) const
	Returns a const pointer to the element at position `p`.

const char *	uniform_name_at (size_t p) const
	Returns the uniform type name for the element at position `p`.

bool	equals (const message &other) const
	Returns `true` if `*this == other, otherwise false.

bool	empty () const
	Returns true if `size() == 0, otherwise false.

template<class T >
const T &	get_as (size_t p) const
	Returns the value at position `p` as const reference of type `T`.

template<class T >
T &	get_as_mutable (size_t p)
	Returns the value at position `p` as mutable reference of type `T`.

optional< message >	apply (message_handler handler)
	Returns `handler(*this)`.

message	extract (message_handler handler) const
	Filters this message by applying slices of it to `handler` and returns the remaining elements of this operation. More...

cli_res	extract_opts (std::vector< cli_arg > xs, help_factory f=nullptr) const
	A simplistic interface for using `extract` to parse command line options. More...

template<class T >
bool	match_element (size_t p) const
	Queries whether the element at position `p` is of type `T`.

template<class... Ts>
bool	match_elements () const
	Queries whether the types of this message are `Ts...`.

Static Public Member Functions
template<class... Ts>
static message	concat (const Ts &...xs)
	Concatinate messages.

Related Functions
(Note that these are not member functions.)
bool	operator== (const message &lhs, const message &rhs)

bool	operator!= (const message &lhs, const message &rhs)

message	operator+ (const message &lhs, const message &rhs)

template<class V , class... Ts>
std::enable_if< !std::is_same< message, typename std::decay< V >::type >::value\|\|(sizeof...(Ts) >) message::type	make_message (V &&x, Ts &&...xs)
	Returns a new `message` containing the values `(x, xs...)`.

message	make_message (message other)
	Returns a copy of `other`.

std::string	to_string (const message &what)

Detailed Description

Describes a fixed-length, copy-on-write, type-erased tuple with elements of any type.

Member Function Documentation

message caf::message::extract ( message_handler handler ) const

Filters this message by applying slices of it to handler and returns the remaining elements of this operation.

Slices are generated in the sequence [0, size), [0, size-1), ... , [1, size-1), ..., [size-1, size). Whenever a slice matches, it is removed from the message and the next slice starts at the same index on the reduced message.

For example:

auto msg = make_message(1, 2.f, 3.f, 4);
// extract float and integer pairs
auto msg2 = msg.extract({
  [](float, float) { },
  [](int, int) { }
});
assert(msg2 == make_message(1, 4));

Step-by-step explanation:

Slice 1: (1, 2.f, 3.f, 4), no match
Slice 2: (1, 2.f, 3.f), no match
Slice 3: (1, 2.f), no match
Slice 4: (1), no match
Slice 5: (2.f, 3.f, 4), no match
Slice 6: (2.f, 3.f), match; new message is (1, 4)
Slice 7: (4), no match

Slice 7 is (4), i.e., does not contain the first element, because the match on slice 6 occurred at index position 1. The function extract iterates a message only once, from left to right.

cli_res caf::message::extract_opts	(	std::vector< cli_arg >	xs,
		help_factory	f = `nullptr`
	)		const

A simplistic interface for using extract to parse command line options.

Usage example:

int main(int argc, char** argv) {
  uint16_t port;
  string host = "localhost";
  auto res = message_builder(argv + 1, argv + argc).extract_opts({
    {"port,p", "set port", port},
    {"host,H", "set host (default: localhost)", host},
    {"verbose,v", "enable verbose mode"}
  });
  if (!res.error.empty()) {
    cerr << res.error << endl;
    return 1;
  }
  if (res.opts.count("help") > 0) {
    // CLI arguments contained "-h", "--help", or "-?" (builtin);
    cout << res.helptext << endl;
    return 0;
  }
  if (!res.remainder.empty()) {
    // ... extract did not consume all CLI arguments ...
  }
  if (res.opts.count("verbose") > 0) {
    // ... enable verbose mode ...
  }
  // ...
}

Parameters

xs	List of argument descriptors.
f	Optional factory function to generate help text (overrides the default generator).

Returns: A struct containing remainder (i.e. unmatched elements), a set containing the names of all used arguments, and the generated help text.

Exceptions

std::invalid_argument if no name or more than one long name is set

Friends And Related Function Documentation

bool operator!=	(	const message &	lhs,
		const message &	rhs
	)

message operator+	(	const message &	lhs,
		const message &	rhs
	)

bool operator==	(	const message &	lhs,
		const message &	rhs
	)

libcaf_core/caf/message.hpp
libcaf_core/caf/string_serialization.hpp

Classes

Public Types

Public Member Functions

Static Public Member Functions

Related Functions

Detailed Description

Member Function Documentation

Friends And Related Function Documentation