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// If expressions have three uses, corresponding to the three types:
// * bool
// * ?T
// * anyerror!T
const expect = @import("std").testing.expect;
test "if expression" {
// If expressions are used instead of a ternary expression.
const a: u32 = 5;
const b: u32 = 4;
const result = if (a != b) 47 else 3089;
try expect(result == 47);
}
test "if boolean" {
// If expressions test boolean conditions.
const a: u32 = 5;
const b: u32 = 4;
if (a != b) {
try expect(true);
} else if (a == 9) {
unreachable;
} else {
unreachable;
}
}
test "if error union" {
// If expressions test for errors.
// Note the |err| capture on the else.
const a: anyerror!u32 = 0;
if (a) |value| {
try expect(value == 0);
} else |err| {
_ = err;
unreachable;
}
const b: anyerror!u32 = error.BadValue;
if (b) |value| {
_ = value;
unreachable;
} else |err| {
try expect(err == error.BadValue);
}
// The else and |err| capture is strictly required.
if (a) |value| {
try expect(value == 0);
} else |_| {}
// To check only the error value, use an empty block expression.
if (b) |_| {} else |err| {
try expect(err == error.BadValue);
}
// Access the value by reference using a pointer capture.
var c: anyerror!u32 = 3;
if (c) |*value| {
value.* = 9;
} else |_| {
unreachable;
}
if (c) |value| {
try expect(value == 9);
} else |_| {
unreachable;
}
}
// test
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