From 35e0b5be0011126bbbb1e1dcc62a497de7dd5385 Mon Sep 17 00:00:00 2001
From: Matty Weatherley <weatherleymatthew@gmail.com>
Date: Mon, 23 Dec 2024 22:09:36 -0500
Subject: [PATCH] Make `bevy_reflect` feature of `bevy_math` non-default
 (#16938)

# Objective

bevy_reflect is a big part of bevy_math's dependency footprint, and is
often not useful when using bevy_math standalone (as I often do). The
goal with this PR is to avoid pulling in those dependencies by default
without compromising the usability of bevy_math types within Bevy
proper.

## Solution

`bevy_reflect` has been removed from default features of `bevy_math`.
However, the feature is enabled by `bevy_internal`, so that
`bevy_reflect` is enabled when `bevy_math` is used through `bevy`.

Philosophically, if there were a feature flag toggling reflection on
`bevy` globally, then whether `bevy_math` enabled `bevy_reflect` itself
would depend on that, but that doesn't exist for the time being.

## Testing

It compiles :)

## Migration Guide

`bevy_reflect` has been made a non-default feature of `bevy_math`. (It
is still enabled when `bevy_math` is used through `bevy`.) You may need
to enable this feature if you are using `bevy_math` on its own and
desire for the types it exports to implement `Reflect` and other
reflection traits.
---
 crates/bevy_internal/Cargo.toml | 4 +++-
 crates/bevy_math/Cargo.toml     | 2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/crates/bevy_internal/Cargo.toml b/crates/bevy_internal/Cargo.toml
index b00b9f6bb4a16..7450c1c3a64a7 100644
--- a/crates/bevy_internal/Cargo.toml
+++ b/crates/bevy_internal/Cargo.toml
@@ -271,7 +271,9 @@ bevy_hierarchy = { path = "../bevy_hierarchy", version = "0.15.0-dev" }
 bevy_input = { path = "../bevy_input", version = "0.15.0-dev" }
 bevy_input_focus = { path = "../bevy_input_focus", version = "0.15.0-dev" }
 bevy_log = { path = "../bevy_log", version = "0.15.0-dev" }
-bevy_math = { path = "../bevy_math", version = "0.15.0-dev" }
+bevy_math = { path = "../bevy_math", version = "0.15.0-dev", features = [
+  "bevy_reflect",
+] }
 bevy_ptr = { path = "../bevy_ptr", version = "0.15.0-dev" }
 bevy_reflect = { path = "../bevy_reflect", version = "0.15.0-dev", features = [
   "bevy",
diff --git a/crates/bevy_math/Cargo.toml b/crates/bevy_math/Cargo.toml
index f635d2a1c1533..c444004521606 100644
--- a/crates/bevy_math/Cargo.toml
+++ b/crates/bevy_math/Cargo.toml
@@ -42,7 +42,7 @@ bevy_math = { path = ".", version = "0.15.0-dev", default-features = false, feat
 glam = { version = "0.29", default-features = false, features = ["approx"] }
 
 [features]
-default = ["std", "rand", "bevy_reflect", "curve"]
+default = ["std", "rand", "curve"]
 std = [
   "alloc",
   "glam/std",