X0100 -- Contract Requires Clause Violated

Reserved code: X0100 is not emitted by the current compiler. A contract violation at runtime prints Contract violation: requires: <clause> with the file and line, without a diagnostic code; use T001 for compile-time type errors. This page is kept for continuity.

A function's requires: precondition was not satisfied at the call site.

Bad Example

fn divide(a: Int, b: Int) -> Int
  requires: b != 0;
{
  return a / b;
}

fn main() -> Int {
  return divide(10, 0);  // X0100: requires b != 0 violated
}

Fix

Guard the call or adjust the arguments:

fn main() -> Int {
  let result = divide(10, 5);  // b is 5, satisfies requires
  return result;
}

Notes

• Contract violations emit @llvm.trap() in debug mode and are treated as safety violations.
• Use --explain X0100 or check contract IR comments (; contract: requires: ...).