Language/Expressions/Constants/math_operators_A03_t03.dart

// Copyright (c) 2021, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

/// @assertion A constant expression is an expression whose value can never
/// change, and that can be evaluated entirely at compile time.
/// The potentially constant expressions and constant expressions are the
/// following:
/// . . .
/// • An expression of the form e1 + e2 is a potentially constant expression if
///   e1 and e2 are both potentially constant expressions. It is further a
///   constant expression if both e1 and e2 are constant expressions and either
///   both evaluate to an instance of int or double, or both evaluate to an
///   instance of String, such that ‘+’ denotes an instance operator invocation.
/// • An expression of the form -e1 is a potentially constant expression if e1
///   is a potentially constant expression. It is further a constant expression
///   if e1 is a constant expression that evaluates to an instance of type int
///   or double, such that ‘-’ denotes an instance operator invocation.
/// • An expression of the form e1 - e2, e1 * e2, e1 / e2, e1 ~/ e2, e1 % e2,
///   e1 < e2, e1 <= e2, e1 > e2, or e1 >= e2 is potentially constant if e1 and
///   e2 are both potentially constant expressions. It is further constant if
///   both e1 and e2 are constant expressions that evaluate to instances of int
///   or double, such that the given operator symbol denotes an invocation of an
///   instance operator
///
/// @description Checks that various expressions of the specified forms can be
/// used within the initializer list of a constant constructor and are,
/// therefore, constant expressions.
/// @author iarkh@unipro.ru

class C {
  const C() :
    a = -1,
    b = -0,
    c = -100500,
    e = -9182319.12394,
    f = -3.14,
    g = -(0.0/0.0),
    h = -(1.0/0.0),
    i = -0.0,

    j = 1 - 2e0,
    k = 1 * 2E-0,
    l = 1 / 2,
    m = 1 > 2,
    n = 1 < 2,
    o = 1 >= 2,
    p = 1 <= 2,
    q = 1 % 2,

    r = 1.42 - 2,
    s = 1.42 * 2,
    t = 1.42 / 2,
    u = 1.42 > 2,
    v = 1.42 < 2,
    w = 1.42 >= 2,
    x = 1.42 <= 2,
    y = 1.42 % 2,

    z = 1 - 2.42,
    aa = 1 * 2.42,
    ab = 1 / 2.42,
    ac = 1 > 2.42,
    ad = 1 < 2.42,
    ae = 1 >= 2.42,
    af = 1 <= 2.42,
    ag = 1 % 2.42,

    ah = 1.42 - 2.42,
    ai = 1.42 * 2.42,
    aj = 1.42 / 2.42,
    ak = 1.42 > 2.42,
    al = 1.42 < 2.42,
    am = 1.42 >= 2.42,
    an = 1.42 <= 2.42,
    ao = 1.42 % 2.42,

    ap = 1.42 ~/ 1.42,
    aq = 5 ~/ 1,
    ar = 0.2 ~/ 2,
    as = 1 ~/ (2 + 1),
    at = 3 ~/ 1.1;

    final a, b, c, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w,
      x, y, z,
      aa, ab, ac, ad, ae, af, ag, ah, ai, aj, ak, al, am, an, ao, ap, aq, ar,
      as, at;
}

main() {
  const C();
}