option.h File Reference

Datatype for wrapping pointer in a safer way. More...

#include <stdbool.h>

Go to the source code of this file.

Data Structures
struct	option_t
	option_t wraps a pointer und does checks whether it is null. More...

Functions
option_t	option (void *data)
	Create a new option_t for given pointer. More...
void *	unwrap (option_t *self)
	Unwrap the option_t and retrieve the underlying pointer. More...
void *	expect (option_t *self, const char *msg)
	Unwraps the option_t and retrieve the underlying pointer. More...
void *	unwrap_or (option_t *self, void *default_val)
	Unwraps the option_t and retrieve the underlying pointer. More...
bool	is_some (option_t *self)
	Check if the underlying data contains a valid pointer. More...
bool	is_none (option_t *self)
	Check if the underlying data is a invalid pointer. More...

Detailed Description

Datatype for wrapping pointer in a safer way.

Function Documentation

void* expect	(	option_t *	self,
		const char *	msg
	)

Unwraps the option_t and retrieve the underlying pointer.

In case of an error see unwrap(), the passed error msg is printed and abort is called.

int *data = malloc(20);
option_t opt = option(data);
void *my_data = opt.expect(&opt, "Data was NULL");

Parameters

self	reference to the option
msg	message to print to stderr

Returns

retrieve the underlying pointer

bool is_none

(

option_t *

self

)

Check if the underlying data is a invalid pointer.

option_t opt = option(NULL);
bool is = opt.is_none(&opt); // returns false

Parameters

self	reference to the option_t

Returns

Is false in case that the pointer passed is NULL

bool is_some

(

option_t *

self

)

Check if the underlying data contains a valid pointer.

int *data = malloc(20);

option_t opt = option(data);
bool is = opt.is_some(&opt); // with a high probability is 1

Parameters

self	reference to the option_t

Returns

true in case that the underlying pointer is not NULL

option_t option

(

void *

data

)

Create a new option_t for given pointer.

int *data = malloc(20);
option_t opt = option(data);

Parameters

data	expects a pointer

Returns

returns a pointer struct which wraps the pointer

void* unwrap

(

option_t *

self

)

Unwrap the option_t and retrieve the underlying pointer.

In case that the underlying data is NULL, abort() is called.

int *data = malloc(20);
option_t opt = option(data);
void *my_data = opt.unwrap(&opt);

Parameters

self	reference to option

Returns

get the underlying data of the option

void* unwrap_or	(	option_t *	self,
		void *	default_val
	)

Unwraps the option_t and retrieve the underlying pointer.

int *data = malloc(20);
int default[20] = {};

option_t opt = option(data);
void *my_data = opt.unwrap_or(&opt, default);

Parameters

self	reference to the option_t
default_val	default value to return

Returns

retrieve the underlying pointer