Function frontOrRethrow
This the the hook implementation for orElseThrow. The makeThrowable predicate is given the exception in this Try if there is one, and the result is throw. Or or the front of the try is returned
auto auto frontOrRethrow(alias makeThrowable, T)
(
auto ref T tryInstance,
string file = __FILE__,
size_t line = __LINE__
)
if (isTry!T);