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Module `dmd.root.optional`

Implementation of an 'Optional' type

Documentation

https://dlang.org/phobos/dmd_root_optional.html

Coverage

https://codecov.io/gh/dlang/dmd/src/master/src/dmd/root/optional.d

Example

import core.exception : AssertError;

Optional!int opt;
assert( opt.isEmpty());
assert(!opt.isPresent());
assert(!opt.hasValue(1));
assert(!opt.hasValue(2));

bool caught;
try
    cast(void) opt.get();
catch (AssertError)
    caught = true;
assert(caught);

opt = Optional!int(1);
assert(!opt.isEmpty());
assert( opt.isPresent());
writeln(opt.get()); // 1
assert( opt.hasValue(1));
assert(!opt.hasValue(2));

Structs

Name	Description
`Optional`	Optional type that is either `empty` or contains a value of type `T`

Authors

Walter Bright

License

Boost License 1.0