D just makes assert() part of the language: https://dlang.org/spec/expression.html#assert_expressions https://dlang.org/spec/expression.html#assert_expressions

D just makes assert() part of the language: https://dlang.org/spec/expression.html#assert_expressions https://dlang.org/spec/expression.html#assert_expressions The behavior of it can be set with a compiler switch to one of: 1. Immediately halting via execution of a special CPU instruction 2. Aborting the program 3. Calling the assert failure function in the corresponding C runtime library 4. Throwing the AssertError exception in the D runtime library So there's no issue with parsing it. The compiler also understands the semantics of assert(), and so things like `assert(0)` can be recognized as being the end of the program.