Function negateCast [src]

Returns the negation of the integer parameter. Result is a signed integer.

Prototype

pub fn negateCast(x: anytype) !std.meta.Int(.signed, @bitSizeOf(@TypeOf(x)))

Example

 test negateCast {
    try testing.expect((negateCast(@as(u32, 999)) catch unreachable) == -999);
    try testing.expect(@TypeOf(negateCast(@as(u32, 999)) catch unreachable) == i32);

    try testing.expect((negateCast(@as(u32, -minInt(i32))) catch unreachable) == minInt(i32));
    try testing.expect(@TypeOf(negateCast(@as(u32, -minInt(i32))) catch unreachable) == i32);

    try testing.expectError(error.Overflow, negateCast(@as(u32, maxInt(i32) + 10)));
}

Source

  pub fn negateCast(x: anytype) !std.meta.Int(.signed, @bitSizeOf(@TypeOf(x))) {
    if (@typeInfo(@TypeOf(x)).int.signedness == .signed) return negate(x);

    const int = std.meta.Int(.signed, @bitSizeOf(@TypeOf(x)));
    if (x > -minInt(int)) return error.Overflow;

    if (x == -minInt(int)) return minInt(int);

    return -@as(int, @intCast(x));
}  