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Function `std.exception.collectExceptionMsg`

Catches the exception thrown from the given expression and returns the msg property of that exception. If no exception is thrown, then null is returned. E can be void.


						
				string collectExceptionMsg(T, E)
				(
				

				  lazy E expression
				

				);

If an exception is thrown but it has an empty message, then emptyExceptionMsg is returned.

Note that while collectExceptionMsg can be used to collect any Throwable and not just Exceptions, it is generally ill-advised to catch anything that is neither an Exception nor a type derived from Exception. So, do not use collectExceptionMsg to collect non-Exceptions unless you're sure that that's what you really want to do.

Parameters

Name	Description
T	The type of exception to catch.
expression	The expression which may throw an exception.

Example

void throwFunc() { throw new Exception("My Message."); }
writeln(collectExceptionMsg(throwFunc())); // "My Message."

void nothrowFunc() {}
assert(collectExceptionMsg(nothrowFunc()) is null);

void throwEmptyFunc() { throw new Exception(""); }
writeln(collectExceptionMsg(throwEmptyFunc())); // emptyExceptionMsg

Authors

Andrei Alexandrescu and Jonathan M Davis

License

Boost License 1.0