Add a const PipeSystem constructor (#7019)

# Objective

Fix #5914.

`PipeSystem` cannot be constructed in `const` contexts.

## Solution

Add a const `PipeSystem::new` function.
This commit is contained in:
JoJoJet 2022-12-25 00:51:19 +00:00
parent a91f89db73
commit 48b4a45d82
2 changed files with 28 additions and 13 deletions

View file

@ -71,16 +71,21 @@ impl<T: SparseSetIndex + fmt::Debug> fmt::Debug for Access<T> {
}
impl<T: SparseSetIndex> Default for Access<T> {
fn default() -> Self {
Self {
reads_all: false,
reads_and_writes: Default::default(),
writes: Default::default(),
marker: PhantomData,
}
Self::new()
}
}
impl<T: SparseSetIndex> Access<T> {
/// Creates an empty [`Access`] collection.
pub const fn new() -> Self {
Self {
reads_all: false,
reads_and_writes: FixedBitSet::new(),
writes: FixedBitSet::new(),
marker: PhantomData,
}
}
/// Increases the set capacity to the specified amount.
///
/// Does nothing if `capacity` is less than or equal to the current value.

View file

@ -54,6 +54,21 @@ pub struct PipeSystem<SystemA, SystemB> {
archetype_component_access: Access<ArchetypeComponentId>,
}
impl<SystemA, SystemB> PipeSystem<SystemA, SystemB> {
/// Manual constructor for creating a [`PipeSystem`].
/// This should only be used when [`IntoPipeSystem::pipe`] cannot be used,
/// such as in `const` contexts.
pub const fn new(system_a: SystemA, system_b: SystemB, name: Cow<'static, str>) -> Self {
Self {
system_a,
system_b,
name,
component_access: Access::new(),
archetype_component_access: Access::new(),
}
}
}
impl<SystemA: System, SystemB: System<In = SystemA::Out>> System for PipeSystem<SystemA, SystemB> {
type In = SystemA::In;
type Out = SystemB::Out;
@ -154,13 +169,8 @@ where
fn pipe(self, system: SystemB) -> PipeSystem<SystemA::System, SystemB::System> {
let system_a = IntoSystem::into_system(self);
let system_b = IntoSystem::into_system(system);
PipeSystem {
name: Cow::Owned(format!("Pipe({}, {})", system_a.name(), system_b.name())),
system_a,
system_b,
archetype_component_access: Default::default(),
component_access: Default::default(),
}
let name = format!("Pipe({}, {})", system_a.name(), system_b.name());
PipeSystem::new(system_a, system_b, Cow::Owned(name))
}
}