55 lines
1.7 KiB
Zig
55 lines
1.7 KiB
Zig
const expect = @import("std").testing.expect;
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// Zig supports hex, octal and binary integer literals.
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const decimal_int: i32 = 98222;
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const hex_int: u8 = 0xff;
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const another_hex_int: u8 = 0xFF;
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const octal_int: u16 = 0o755;
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const binary_int: u8 = 0b11110000;
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// Underscores may also be placed between digits as a visual separator.
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const one_billion: u64 = 1_000_000_000;
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const binary_mask: u64 = 0b1_1111_1111;
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const permissions: u64 = 0o7_5_5;
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const big_address: u64 = 0xFF80_0000_0000_0000;
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// "Integer Widening" is allowed,
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// which means that integers of a type may coerce to an integer of another type,
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// providing that the new type can fit all of the values that the old type can.
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test "integer widening" {
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const a: u8 = 250;
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const b: u16 = a;
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const c: u32 = b;
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try expect(c == a);
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}
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// If you have a value stored in an integer that cannot coerce to the type that you want,
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// `@intCast` may be used to explicitly convert from one type to the other.
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// If the value given is out of the range of the destination type, this is detectable illegal behaviour.
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test "@intCast" {
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const x: u64 = 200;
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const y = @as(u8, @intCast(x));
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try expect(@TypeOf(y) == u8);
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}
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// Integers, by default, are not allowed to overflow. Overflows are detectable illegal behaviour.
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// Sometimes, being able to overflow integers in a well-defined manner is a wanted behaviour.
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// For this use case, Zig provides overflow operators.
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// | Normal Operator | Wrapping Operator |
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// | `+` | `+%` |
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// | `-` | `-%` |
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// | `*` | `*%` |
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// | `+=` | `+=%` |
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// | `-=` | `-=%` |
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// | `*=` | `*=%` |
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test "well defined overflow" {
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var a: u8 = 255;
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a +%= 1;
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try expect(a == 0);
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}
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