pub struct Char(pub c_char);
Expand description

Wrapper for values where C functions expect a plain C char

Consider the following C function prototype from glib:

void g_key_file_set_list_separator (GKeyFile *key_file, gchar separator);

This function plainly expects a byte as the separator argument. However, having this function exposed to Rust as the following would be inconvenient:

impl KeyFile {
    pub fn set_list_separator(&self, separator: libc:c_char) { }
}

This would be inconvenient because users would have to do the conversion from a Rust char to an libc::c_char by hand, which is just a type alias for i8 on most system.

This Char type is a wrapper over an libc::c_char, so that we can pass it to Glib or C functions. The check for whether a Rust char (a Unicode scalar value) actually fits in a libc::c_char is done in the new function; see its documentation for details.

The inner libc::c_char (which is equivalent to i8) can be extracted with .0, or by calling my_char.into_glib().

Examples

use glib::Char;
use std::convert::TryFrom;

Char::from(b'a');
Char::try_from('a').unwrap();
assert!(Char::try_from('☔').is_err());
extern "C" fn have_a_byte(b: libc::c_char);

have_a_byte(Char::from(b'a').into_glib());

Tuple Fields

0: c_char

Trait Implementations

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

Formats the value using the given formatter. Read more

Converts to this type from the input type.

Converts to this type from the input type.

Converts to this type from the input type.

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

The type returned in the event of a conversion error.

Performs the conversion.

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The resulting type after obtaining ownership.

Creates owned data from borrowed data, usually by cloning. Read more

Uses borrowed data to replace owned data, usually by cloning. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.