langref: update for opaque {} syntax

Author: tadeokondrak

doc/docgen.zig

@@ -808,6 +808,7 @@ fn tokenizeAndPrintRaw(docgen_tokenizer: *Tokenizer, out: anytype, source_token:
             .Keyword_noalias,
             .Keyword_noinline,
             .Keyword_nosuspend,
+            .Keyword_opaque,
             .Keyword_or,
             .Keyword_orelse,
             .Keyword_packed,

doc/langref.html.in

@@ -1988,7 +1988,7 @@ 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|opaque type|Opaque Types#}.</li>
+              {#syntax#}c_void{#endsyntax#} or any other {#link|opaque type|opaque#}.</li>
             </ul>
           </li>
       </ul>
@@ -5545,7 +5545,7 @@ test "turn HashMap into a set with void" {
       </p>
       <p>
       {#syntax#}void{#endsyntax#} is distinct from {#syntax#}c_void{#endsyntax#}, which is defined like this:
-              {#syntax#}pub const c_void = @Type(.Opaque);{#endsyntax#}.
+              {#syntax#}pub const c_void = 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>
@@ -8471,7 +8471,7 @@ test "integer truncation" {
           <li>{#link|Error Set Type#}</li>
           <li>{#link|Error Union Type#}</li>
           <li>{#link|Vectors#}</li>
-          <li>{#link|Opaque Types#}</li>
+          <li>{#link|opaque#}</li>
           <li>{#link|@Frame#}</li>
           <li>{#syntax#}anyframe{#endsyntax#}</li>
           <li>{#link|struct#}</li>
@@ -8547,17 +8547,18 @@ fn foo(comptime T: type, ptr: *T) T {
       {#header_close#}
       {#header_close#}
 
-      {#header_open|Opaque Types#}
+      {#header_open|opaque#}
       <p>
-      {#syntax#}@Type(.Opaque){#endsyntax#} creates a new type with an unknown (but non-zero) size and alignment.
+      {#syntax#}opaque {}{#endsyntax#} declares a new type with an unknown (but non-zero) size and alignment.
+      It can have declarations like structs, unions, or enums.
       </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);
+const Derp = opaque {};
+const Wat = opaque {};
 
 extern fn bar(d: *Derp) void;
 fn foo(w: *Wat) callconv(.C) void {