Simplify templates

docs/source/languages/cpp.md

@@ -242,14 +242,19 @@ provide the following functions to aide in the serialization process:
     }
 ```
 
--   `native_type_template("type<{{T}}>")` (on a struct) together with
+-   `native_type_template("type")` (on a struct) together with
     `native_type_template_arg("type")` (on a field of that struct type):
     lets a single struct declaration back a native type that is a C++
     template, instantiated differently per field, instead of requiring one
-    struct declaration (and `native_type`) per instantiation. For example:
+    struct declaration (and `native_type`) per instantiation.
+    `native_type_template_arg` is angle-bracket-appended to
+    `native_type_template` to form the field's native type, so
+    `native_type_template: "Native::Box"` with
+    `native_type_template_arg: "Native::TypeA"` produces
+    `Native::Box<Native::TypeA>`. For example:
 
 ```cpp
-    struct Box (native_type_template: "Native::Box<{{T}}>") {
+    struct Box (native_type_template: "Native::Box") {
       value: int32;
     }
 
@@ -271,10 +276,10 @@ is equivalent to writing, on each field itself:
 functions stay unique across instantiations without spelling it out
 yourself; an explicit `native_type_pack_name` on the field still overrides
 this. More than one template parameter is supported by separating them with
-commas and using indexed placeholders:
+commas:
 
 ```cpp
-    struct Pair (native_type_template: "Native::Pair<{{T0}}, {{T1}}>") {
+    struct Pair (native_type_template: "Native::Pair") {
       value: int32;
     }
 
@@ -283,6 +288,7 @@ commas and using indexed placeholders:
     }
 ```
 
+which produces `Native::Pair<Native::Key, Native::Value>`.
 `native_type_template_arg` is only valid on fields whose type is a struct
 (or vector of structs) that declares `native_type_template`.