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Function std.exception.assertNotThrown

Asserts that the given expression does not throw the given type of Throwable. If a Throwable of the given type is thrown, it is caught and does not escape assertNotThrown. Rather, an AssertError is thrown. However, any other Throwables will escape.

auto assertNotThrown(T, E) (
  lazy E expression,
  string msg = null,
  string file = __FILE__,
  size_t line = __LINE__


T The Throwable to test for.
expression The expression to test.
msg Optional message to output on test failure. If msg is empty, and the thrown exception has a non-empty msg field, the exception's msg field will be output on test failure.
file The file where the error occurred. Defaults to __FILE__.
line The line where the error occurred. Defaults to __LINE__.


AssertError if the given Throwable is thrown.


the result of expression.


import core.exception : AssertError;

import std.string;
assertNotThrown!StringException(enforce!StringException(true, "Error!"));

//Exception is the default.
assertNotThrown(enforce!StringException(true, "Error!"));

           enforce!StringException(false, "Error!"))) ==
       `assertNotThrown failed: StringException was thrown: Error!`);


Andrei Alexandrescu and Jonathan M Davis


Boost License 1.0