Slightly improve performance of builders

Builders would keep a `serde_json::Map<String, Value>`, which would
require re-creating owned strings for the same parameter multiple times
in some cases, depending on builder defaults and keying strategies.

This commit uses a `std::collections::HashMap<&'static str, Value>`
internally, and moves over values to a `serde_json::Map<String, Value>`
when it comes time to sending them to the appropriate `http` module
function.

This saves the number of heap-allocated string creations on most
builders, with specific performance increase on `builder::CreateMessage`
and `builder::CreateEmbed` & co.

1 files changed, 5 insertions, 3 deletions

diff --git a/src/model/invite.rs b/src/model/invite.rs
index b4f326c..8ef848c 100644
--- a/src/model/invite.rs
+++ b/src/model/invite.rs
@@ -6,9 +6,9 @@ use super::{Permissions, utils as model_utils};
 #[cfg(feature = "model")]
 use builder::CreateInvite;
 #[cfg(feature = "model")]
-use http;
-#[cfg(feature = "model")]
 use internal::prelude::*;
+#[cfg(feature = "model")]
+use {http, utils};
 
 /// Information about an invite code.
 ///
@@ -73,7 +73,9 @@ impl Invite {
             }
         }
 
-        http::create_invite(channel_id.0, &f(CreateInvite::default()).0)
+        let map = utils::hashmap_to_json_map(f(CreateInvite::default()).0);
+
+        http::create_invite(channel_id.0, &map)
     }
 
     /// Deletes the invite.