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Update language reference for recent @Type changes

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Tadeo Kondrak 2020-04-27 23:23:13 -06:00
parent 17e41f6cd3
commit 2ef0795bfb
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1 changed files with 30 additions and 32 deletions
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doc/langref.html.in
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@ -1885,7 +1885,7 @@ test "null terminated array" {
<li>Supports slice syntax: {#syntax#}ptr[start..end]{#endsyntax#}</li>
<li>Supports pointer arithmetic: {#syntax#}ptr + x{#endsyntax#}, {#syntax#}ptr - x{#endsyntax#}</li>
<li>{#syntax#}T{#endsyntax#} must have a known size, which means that it cannot be
{#syntax#}c_void{#endsyntax#} or any other {#link|@OpaqueType#}.</li>
{#syntax#}c_void{#endsyntax#} or any other {#link|opaque type|Opaque Types#}.</li>
</ul>
</li>
</ul>
@ -5392,7 +5392,7 @@ fn eql_i32(a: i32, b: i32) bool {
</p>
<p>
{#syntax#}void{#endsyntax#} is distinct from {#syntax#}c_void{#endsyntax#}, which is defined like this:
{#syntax#}pub const c_void = @OpaqueType();{#endsyntax#}.
{#syntax#}pub const c_void = @Type(.Opaque);{#endsyntax#}.
{#syntax#}void{#endsyntax#} has a known size of 0 bytes, and {#syntax#}c_void{#endsyntax#} has an unknown, but non-zero, size.
</p>
<p>
@ -7666,30 +7666,6 @@ mem.set(u8, dest, c);{#endsyntax#}</pre>
</p>
{#header_close#}
{#header_open|@OpaqueType#}
<pre>{#syntax#}@OpaqueType() type{#endsyntax#}</pre>
<p>
Creates a new type with an unknown (but non-zero) size and alignment.
</p>
<p>
This is typically used for type safety when interacting with C code that does not expose struct details.
Example:
</p>
{#code_begin|test_err|expected type '*Derp', found '*Wat'#}
const Derp = @OpaqueType();
const Wat = @OpaqueType();
extern fn bar(d: *Derp) void;
fn foo(w: *Wat) callconv(.C) void {
bar(w);
}
test "call foo" {
foo(undefined);
}
{#code_end#}
{#header_close#}
{#header_open|@panic#}
<pre>{#syntax#}@panic(message: []const u8) noreturn{#endsyntax#}</pre>
<p>
@ -8274,21 +8250,21 @@ test "integer truncation" {
<li>{#syntax#}comptime_float{#endsyntax#}</li>
<li>{#syntax#}@TypeOf(undefined){#endsyntax#}</li>
<li>{#syntax#}@TypeOf(null){#endsyntax#}</li>
<li>{#link|Arrays#}</li>
<li>{#link|Optionals#}</li>
<li>{#link|Error Union Type#}</li>
<li>{#link|Vectors#}</li>
<li>{#link|Opaque Types#}</li>
<li>AnyFrame</li>
</ul>
<p>
For these types it is a
<a href="https://github.com/ziglang/zig/issues/2907">TODO in the compiler to implement</a>:
</p>
<ul>
<li>Array</li>
<li>Optional</li>
<li>ErrorUnion</li>
<li>ErrorSet</li>
<li>Enum</li>
<li>Opaque</li>
<li>FnFrame</li>
<li>AnyFrame</li>
<li>Vector</li>
<li>EnumLiteral</li>
</ul>
<p>
@ -8373,6 +8349,28 @@ fn foo(comptime T: type, ptr: *T) T {
{#header_close#}
{#header_close#}
{#header_open|Opaque Types#}
{#syntax#}@Type(.Opaque){#endsyntax#} creates a new type with an unknown (but non-zero) size and alignment.
</p>
<p>
This is typically used for type safety when interacting with C code that does not expose struct details.
Example:
</p>
{#code_begin|test_err|expected type '*Derp', found '*Wat'#}
const Derp = @Type(.Opaque);
const Wat = @Type(.Opaque);
extern fn bar(d: *Derp) void;
fn foo(w: *Wat) callconv(.C) void {
bar(w);
}
test "call foo" {
foo(undefined);
}
{#code_end#}
{#header_close#}
{#header_open|Build Mode#}
<p>
Zig has four build modes: