#lang racket
(require [only-in plait test test/exn error print-only-errors])

(define-syntax-rule (strict-if C T E)
  (if (boolean? C)
      (if C T E)
      (error 'strict-if "expected a boolean")))

(test (strict-if true 1 (/ 1 0)) 1)
(test/exn (strict-if 0 1 (/ 1 0)) "expected a boolean")