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Template std.variant.tryVisit
Behaves as visit
If a parameter-less function is specified it is called when
either variant doesn't hold a value or holds a type
which isn't handled by the visiting functions.
Arguments
template tryVisit(Handler...);
Functions
| Function name | Description |
|---|---|
| tryVisit |
Returns
The return type of tryVisit is deduced from the visiting functions and must be
the same across all overloads.
Throws
If no parameter-less, error function is specified: VariantExceptionvariant doesn't hold a value or
if variant holds a value which isn't handled by the visiting
functions.
Example
Algebraic!(int, string) variant; variant = 10; auto which = -1; variant.tryVisit!((int i) { which = 0; })(); assert(which == 0); // Error function usage variant = "test"; variant.tryVisit!((int i) { which = 0; }, () { which = -100; })(); assert(which == -100);