ASSERT

ASSERT Expression [ PRINT ... ] ASSERT Expression [ ERROR ... ]

Поскольку 3.13

Check that Expression is TRUE, and if the Expression is FALSE, an uncatchable "Assertion failed" error is raised, the PRINT or ERROR instruction is executed, and the program stops immediately.

The ASSERT instruction was actually introduced in Gambas 3.12, but without having the possibility to print a message.

See also