generated docs: progress towards generic types being useful

See #3406

Author: andrewrk

lib/std/hash_map.zig

@@ -36,7 +36,8 @@ pub fn HashMap(comptime K: type, comptime V: type, comptime hash: fn (key: K) u3
         size: usize,
         max_distance_from_start_index: usize,
         allocator: *Allocator,
-        // this is used to detect bugs where a hashtable is edited while an iterator is running.
+
+        /// This is used to detect bugs where a hashtable is edited while an iterator is running.
         modification_count: debug_u32,
 
         const Self = @This();

lib/std/meta.zig

@@ -542,3 +542,13 @@ pub fn intToEnum(comptime Tag: type, tag_int: var) IntToEnumError!Tag {
     }
     return error.InvalidEnumTag;
 }
+
+/// Given a type and a name, return the field index according to source order.
+/// Returns `null` if the field is not found.
+pub fn fieldIndex(comptime T: type, comptime name: []const u8) ?comptime_int {
+    inline for (fields(T)) |field, i| {
+        if (mem.eql(u8, field.name, name))
+            return comptime_int(i);
+    }
+    return null;
+}

lib/std/special/docs/index.html

@@ -104,6 +104,16 @@
         background-color: #FFBB4D;
         color: #000;
       }
+      #listFnExamples {
+        list-style-type: none;
+        margin: 0;
+        padding: 0;
+      }
+      #listFnExamples li {
+        padding: 0.5em 0;
+        white-space: nowrap;
+        overflow-x: auto;
+      }
       #logo {
         width: 8em;
         padding: 0.5em 1em;
@@ -289,7 +299,6 @@ <h2>Target</h2>
       <pre id="fnProtoCode"></pre>
     </div>
     <h1 id="hdrName" class="hidden"></h1>
-    <div id="fnExamples" class="hidden"></div>
     <div id="fnNoExamples" class="hidden">
       <p>This function is not tested or referenced.</p>
     </div>
@@ -357,6 +366,10 @@ <h2>Error Sets</h2>
       <ul id="listErrSets">
       </ul>
     </div>
+    <div id="fnExamples" class="hidden">
+        <h2>Examples</h2>
+        <ul id="listFnExamples"></ul>
+    </div>
     </section>
     <div id="helpDialog" class="hidden">
       <h1>Keyboard Shortcuts</h1>