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Function std.utf.decodeBack
decodeBack
is a variant of decode
which specifically decodes
the last code point. Unlike decode
, decodeBack
accepts any
bidirectional range of code units (rather than just a string or random access
range). It also takes the range by ref
and pops off the elements as it
decodes them. If numCodeUnits
is passed in, it gets set to the number
of code units which were in the code point which was decoded.
dchar decodeBack(Flag!("useReplacementDchar") useReplacementDchar = No .useReplacementDchar, S)
(
ref S str,
out size_t numCodeUnits
)
if (isSomeString!S);
dchar decodeBack(Flag!("useReplacementDchar") useReplacementDchar = No .useReplacementDchar, S)
(
ref S str,
out size_t numCodeUnits
)
if (!isSomeString!S && isSomeChar!(ElementType!S) && isBidirectionalRange!S && (isRandomAccessRange!S && hasLength!S || !isRandomAccessRange!S));
dchar decodeBack(Flag!("useReplacementDchar") useReplacementDchar = No .useReplacementDchar, S)
(
ref S str
)
if (isSomeString!S || isRandomAccessRange!S && hasLength!S && isSomeChar!(ElementType!S) || !isRandomAccessRange!S && isBidirectionalRange!S && isSomeChar!(ElementType!S));
Parameters
Name | Description |
---|---|
useReplacementDchar | if invalid UTF, return replacementDchar rather than throwing |
str | input string or bidirectional Range |
numCodeUnits | gives the number of code units processed |
Returns
A decoded UTF character.
Throws
UTFException
if str
is not the end of a valid UTF
sequence. If an exception is thrown, the str
itself remains unchanged,
but there is no guarantee as to the value of numCodeUnits
(when passed).
Example
import std .range .primitives;
string str = "Hello, World!";
assert(str .decodeBack == '!' && str == "Hello, World");
str = "å";
assert(str .decodeBack == 'å' && str .empty);
str = "å";
size_t i;
assert(str .decodeBack(i) == 'å' && i == 2 && str .empty);
Authors
License
Copyright © 1999-2022 by the D Language Foundation | Page generated by ddox.