Safety and attributes

Safety and attributes

Core calculations are annotated @safe pure nothrow @nogc where the compiler verifies those properties. The examples/no_gc.d example places grid creation inside a function that carries all four attributes; compiling it is a compiler-checked attribute test.

Direct aggregate construction can represent invalid CivilDate fields. Call isValid or use tryMake at input boundaries. Operations that can fail at supported-year edges return bool and an output value instead of silently wrapping.

No system clock or time-zone conversion is performed. The library models civil dates only; it does not claim to convert instants or resolve DST gaps.

The core module also compiles with BetterC when the formatting-only YearMonth.toString member is excluded by the compiler’s D_BetterC version. BetterC users retain the date, grid, mask, blank-grid, and fingerprint APIs; string formatting is intentionally runtime-library dependent.