Type Function IntFittingRange [src]

Returns the smallest integer type that can hold both from and to.

Prototype

pub fn IntFittingRange(comptime from: comptime_int, comptime to: comptime_int) type

Parameters

from: comptime_intto: comptime_int

Example

 test IntFittingRange {
    try testing.expect(IntFittingRange(0, 0) == u0);
    try testing.expect(IntFittingRange(0, 1) == u1);
    try testing.expect(IntFittingRange(0, 2) == u2);
    try testing.expect(IntFittingRange(0, 3) == u2);
    try testing.expect(IntFittingRange(0, 4) == u3);
    try testing.expect(IntFittingRange(0, 7) == u3);
    try testing.expect(IntFittingRange(0, 8) == u4);
    try testing.expect(IntFittingRange(0, 9) == u4);
    try testing.expect(IntFittingRange(0, 15) == u4);
    try testing.expect(IntFittingRange(0, 16) == u5);
    try testing.expect(IntFittingRange(0, 17) == u5);
    try testing.expect(IntFittingRange(0, 4095) == u12);
    try testing.expect(IntFittingRange(2000, 4095) == u12);
    try testing.expect(IntFittingRange(0, 4096) == u13);
    try testing.expect(IntFittingRange(2000, 4096) == u13);
    try testing.expect(IntFittingRange(0, 4097) == u13);
    try testing.expect(IntFittingRange(2000, 4097) == u13);
    try testing.expect(IntFittingRange(0, 123456789123456798123456789) == u87);
    try testing.expect(IntFittingRange(0, 123456789123456798123456789123456789123456798123456789) == u177);

    try testing.expect(IntFittingRange(-1, -1) == i1);
    try testing.expect(IntFittingRange(-1, 0) == i1);
    try testing.expect(IntFittingRange(-1, 1) == i2);
    try testing.expect(IntFittingRange(-2, -2) == i2);
    try testing.expect(IntFittingRange(-2, -1) == i2);
    try testing.expect(IntFittingRange(-2, 0) == i2);
    try testing.expect(IntFittingRange(-2, 1) == i2);
    try testing.expect(IntFittingRange(-2, 2) == i3);
    try testing.expect(IntFittingRange(-1, 2) == i3);
    try testing.expect(IntFittingRange(-1, 3) == i3);
    try testing.expect(IntFittingRange(-1, 4) == i4);
    try testing.expect(IntFittingRange(-1, 7) == i4);
    try testing.expect(IntFittingRange(-1, 8) == i5);
    try testing.expect(IntFittingRange(-1, 9) == i5);
    try testing.expect(IntFittingRange(-1, 15) == i5);
    try testing.expect(IntFittingRange(-1, 16) == i6);
    try testing.expect(IntFittingRange(-1, 17) == i6);
    try testing.expect(IntFittingRange(-1, 4095) == i13);
    try testing.expect(IntFittingRange(-4096, 4095) == i13);
    try testing.expect(IntFittingRange(-1, 4096) == i14);
    try testing.expect(IntFittingRange(-4097, 4095) == i14);
    try testing.expect(IntFittingRange(-1, 4097) == i14);
    try testing.expect(IntFittingRange(-1, 123456789123456798123456789) == i88);
    try testing.expect(IntFittingRange(-1, 123456789123456798123456789123456789123456798123456789) == i178);
}

Source

  pub fn IntFittingRange(comptime from: comptime_int, comptime to: comptime_int) type {
    assert(from <= to);
    const signedness: std.builtin.Signedness = if (from < 0) .signed else .unsigned;
    return @Type(.{ .int = .{
        .signedness = signedness,
        .bits = @as(u16, @intFromBool(signedness == .signed)) +
            switch (if (from < 0) @max(@abs(from) - 1, to) else to) {
                0 => 0,
                else => |pos_max| 1 + log2(pos_max),
            },
    } });
}  