zig/test/cases/generics.zig
Andrew Kelley af536ac343 introduce new test syntax
* remove setFnTest builtin
 * add test "name" { ... } syntax
 * remove --check-unused argument. functions are always lazy now.
2017-03-16 16:02:35 -04:00

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const assert = @import("std").debug.assert;
test "simpleGenericFn" {
assert(max(i32, 3, -1) == 3);
assert(max(f32, 0.123, 0.456) == 0.456);
assert(add(2, 3) == 5);
}
fn max(comptime T: type, a: T, b: T) -> T {
return if (a > b) a else b;
}
fn add(comptime a: i32, b: i32) -> i32 {
return (comptime {a}) + b;
}
const the_max = max(u32, 1234, 5678);
test "compileTimeGenericEval" {
assert(the_max == 5678);
}
fn gimmeTheBigOne(a: u32, b: u32) -> u32 {
max(u32, a, b)
}
fn shouldCallSameInstance(a: u32, b: u32) -> u32 {
max(u32, a, b)
}
fn sameButWithFloats(a: f64, b: f64) -> f64 {
max(f64, a, b)
}
test "fnWithInlineArgs" {
assert(gimmeTheBigOne(1234, 5678) == 5678);
assert(shouldCallSameInstance(34, 12) == 34);
assert(sameButWithFloats(0.43, 0.49) == 0.49);
}
test "varParams" {
assert(max_i32(12, 34) == 34);
assert(max_f64(1.2, 3.4) == 3.4);
}
// TODO `_`
const _1 = assert(max_i32(12, 34) == 34);
const _2 = assert(max_f64(1.2, 3.4) == 3.4);
fn max_var(a: var, b: var) -> @typeOf(a + b) {
if (a > b) a else b
}
fn max_i32(a: i32, b: i32) -> i32 {
max_var(a, b)
}
fn max_f64(a: f64, b: f64) -> f64 {
max_var(a, b)
}
pub fn List(comptime T: type) -> type {
SmallList(T, 8)
}
pub fn SmallList(comptime T: type, comptime STATIC_SIZE: usize) -> type {
struct {
items: []T,
length: usize,
prealloc_items: [STATIC_SIZE]T,
}
}
test "functionWithReturnTypeType" {
var list: List(i32) = undefined;
var list2: List(i32) = undefined;
list.length = 10;
list2.length = 10;
assert(list.prealloc_items.len == 8);
assert(list2.prealloc_items.len == 8);
}
test "genericStruct" {
var a1 = GenNode(i32) {.value = 13, .next = null,};
var b1 = GenNode(bool) {.value = true, .next = null,};
assert(a1.value == 13);
assert(a1.value == a1.getVal());
assert(b1.getVal());
}
fn GenNode(comptime T: type) -> type {
struct {
value: T,
next: ?&GenNode(T),
fn getVal(n: &const GenNode(T)) -> T { n.value }
}
}
test "constDeclsInStruct" {
assert(GenericDataThing(3).count_plus_one == 4);
}
fn GenericDataThing(comptime count: isize) -> type {
struct {
const count_plus_one = count + 1;
}
}
test "useGenericParamInGenericParam" {
assert(aGenericFn(i32, 3, 4) == 7);
}
fn aGenericFn(comptime T: type, comptime a: T, b: T) -> T {
return a + b;
}
test "genericFnWithImplicitCast" {
assert(getFirstByte(u8, []u8 {13}) == 13);
assert(getFirstByte(u16, []u16 {0, 13}) == 0);
}
fn getByte(ptr: ?&const u8) -> u8 {*??ptr}
fn getFirstByte(comptime T: type, mem: []const T) -> u8 {
getByte((&const u8)(&mem[0]))
}