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-rw-r--r--syn/examples/heapsize/Cargo.toml2
-rw-r--r--syn/examples/heapsize/README.md72
-rw-r--r--syn/examples/heapsize/example/Cargo.toml9
-rw-r--r--syn/examples/heapsize/example/src/main.rs28
-rw-r--r--syn/examples/heapsize/heapsize/Cargo.toml9
-rw-r--r--syn/examples/heapsize/heapsize/src/lib.rs64
-rw-r--r--syn/examples/heapsize/heapsize_derive/Cargo.toml14
-rw-r--r--syn/examples/heapsize/heapsize_derive/src/lib.rs96
8 files changed, 0 insertions, 294 deletions
diff --git a/syn/examples/heapsize/Cargo.toml b/syn/examples/heapsize/Cargo.toml
deleted file mode 100644
index 9b19214..0000000
--- a/syn/examples/heapsize/Cargo.toml
+++ /dev/null
@@ -1,2 +0,0 @@
-[workspace]
-members = ["example", "heapsize", "heapsize_derive"]
diff --git a/syn/examples/heapsize/README.md b/syn/examples/heapsize/README.md
deleted file mode 100644
index e789559..0000000
--- a/syn/examples/heapsize/README.md
+++ /dev/null
@@ -1,72 +0,0 @@
-A derive macro that generates trait impls.
-
-- [`heapsize/src/lib.rs`](heapsize/src/lib.rs)
-- [`heapsize_derive/src/lib.rs`](heapsize_derive/src/lib.rs)
-- [`example/src/main.rs`](example/src/main.rs)
-
-We are deriving the `HeapSize` trait which computes an estimate of the amount of
-heap memory owned by a value.
-
-```rust
-pub trait HeapSize {
- /// Total number of bytes of heap memory owned by `self`.
- fn heap_size_of_children(&self) -> usize;
-}
-```
-
-The derive macro allows users to write `#[derive(HeapSize)]` on data structures
-in their program.
-
-```rust
-#[derive(HeapSize)]
-struct Demo<'a, T: ?Sized> {
- a: Box<T>,
- b: u8,
- c: &'a str,
- d: String,
-}
-```
-
-The trait impl generated by the derive macro here would look like:
-
-```rust
-impl<'a, T: ?Sized + heapsize::HeapSize> heapsize::HeapSize for Demo<'a, T> {
- fn heap_size_of_children(&self) -> usize {
- 0 + heapsize::HeapSize::heap_size_of_children(&self.a)
- + heapsize::HeapSize::heap_size_of_children(&self.b)
- + heapsize::HeapSize::heap_size_of_children(&self.c)
- + heapsize::HeapSize::heap_size_of_children(&self.d)
- }
-}
-```
-
-The implementation of `heapsize_derive` demonstrates some attention to "spans"
-of error messages. For each subexpression in the generated code we apply the
-span of the input fragment under which we would want to trigger a compiler error
-if the subexpression fails to compile. In this example, each recursive call to
-`heap_size_of_children` is associated with the span of the corresponding struct
-field. Thus we get errors in the right place if any of the field types do not
-implement the `HeapSize` trait.
-
-```
-error[E0277]: the trait bound `std::thread::Thread: HeapSize` is not satisfied
- --> src/main.rs:7:5
- |
-7 | bad: std::thread::Thread,
- | ^^^ the trait `HeapSize` is not implemented for `std::thread::Thread`
-```
-
-Some unstable APIs in the `proc-macro2` crate let us improve this further by
-joining together the span of the field name and the field type. There is no
-difference in our code &mdash; everything is as shown in this directory &mdash;
-but building the example crate with `cargo build` shows errors like the one
-above and building with `RUSTFLAGS='--cfg procmacro2_semver_exempt' cargo build`
-is able to show errors like the following.
-
-```
-error[E0277]: the trait bound `std::thread::Thread: HeapSize` is not satisfied
- --> src/main.rs:7:5
- |
-7 | bad: std::thread::Thread,
- | ^^^^^^^^^^^^^^^^^^^^^^^^ the trait `HeapSize` is not implemented for `std::thread::Thread`
-```
diff --git a/syn/examples/heapsize/example/Cargo.toml b/syn/examples/heapsize/example/Cargo.toml
deleted file mode 100644
index 85c7699..0000000
--- a/syn/examples/heapsize/example/Cargo.toml
+++ /dev/null
@@ -1,9 +0,0 @@
-[package]
-name = "heapsize_example"
-version = "0.0.0"
-authors = ["David Tolnay <dtolnay@gmail.com>"]
-edition = "2018"
-publish = false
-
-[dependencies]
-heapsize = { path = "../heapsize" }
diff --git a/syn/examples/heapsize/example/src/main.rs b/syn/examples/heapsize/example/src/main.rs
deleted file mode 100644
index 9332b11..0000000
--- a/syn/examples/heapsize/example/src/main.rs
+++ /dev/null
@@ -1,28 +0,0 @@
-use heapsize::HeapSize;
-
-#[derive(HeapSize)]
-struct Demo<'a, T: ?Sized> {
- a: Box<T>,
- b: u8,
- c: &'a str,
- d: String,
-}
-
-fn main() {
- let demo = Demo {
- a: b"bytestring".to_vec().into_boxed_slice(),
- b: 255,
- c: "&'static str",
- d: "String".to_owned(),
- };
-
- // 10 + 0 + 0 + 6 = 16
- println!(
- "heap size = {} + {} + {} + {} = {}",
- demo.a.heap_size_of_children(),
- demo.b.heap_size_of_children(),
- demo.c.heap_size_of_children(),
- demo.d.heap_size_of_children(),
- demo.heap_size_of_children()
- );
-}
diff --git a/syn/examples/heapsize/heapsize/Cargo.toml b/syn/examples/heapsize/heapsize/Cargo.toml
deleted file mode 100644
index 27bb954..0000000
--- a/syn/examples/heapsize/heapsize/Cargo.toml
+++ /dev/null
@@ -1,9 +0,0 @@
-[package]
-name = "heapsize"
-version = "0.0.0"
-authors = ["David Tolnay <dtolnay@gmail.com>"]
-edition = "2018"
-publish = false
-
-[dependencies]
-heapsize_derive = { path = "../heapsize_derive" }
diff --git a/syn/examples/heapsize/heapsize/src/lib.rs b/syn/examples/heapsize/heapsize/src/lib.rs
deleted file mode 100644
index 30bb6d6..0000000
--- a/syn/examples/heapsize/heapsize/src/lib.rs
+++ /dev/null
@@ -1,64 +0,0 @@
-use std::mem;
-
-pub use heapsize_derive::*;
-
-pub trait HeapSize {
- /// Total number of bytes of heap memory owned by `self`.
- ///
- /// Does not include the size of `self` itself, which may or may not be on
- /// the heap. Includes only children of `self`, meaning things pointed to by
- /// `self`.
- fn heap_size_of_children(&self) -> usize;
-}
-
-//
-// In a real version of this library there would be lots more impls here, but
-// here are some interesting ones.
-//
-
-impl HeapSize for u8 {
- /// A `u8` does not own any heap memory.
- fn heap_size_of_children(&self) -> usize {
- 0
- }
-}
-
-impl HeapSize for String {
- /// A `String` owns enough heap memory to hold its reserved capacity.
- fn heap_size_of_children(&self) -> usize {
- self.capacity()
- }
-}
-
-impl<T> HeapSize for Box<T>
-where
- T: ?Sized + HeapSize,
-{
- /// A `Box` owns however much heap memory was allocated to hold the value of
- /// type `T` that we placed on the heap, plus transitively however much `T`
- /// itself owns.
- fn heap_size_of_children(&self) -> usize {
- mem::size_of_val(&**self) + (**self).heap_size_of_children()
- }
-}
-
-impl<T> HeapSize for [T]
-where
- T: HeapSize,
-{
- /// Sum of heap memory owned by each element of a dynamically sized slice of
- /// `T`.
- fn heap_size_of_children(&self) -> usize {
- self.iter().map(HeapSize::heap_size_of_children).sum()
- }
-}
-
-impl<'a, T> HeapSize for &'a T
-where
- T: ?Sized,
-{
- /// A shared reference does not own heap memory.
- fn heap_size_of_children(&self) -> usize {
- 0
- }
-}
diff --git a/syn/examples/heapsize/heapsize_derive/Cargo.toml b/syn/examples/heapsize/heapsize_derive/Cargo.toml
deleted file mode 100644
index f4357b9..0000000
--- a/syn/examples/heapsize/heapsize_derive/Cargo.toml
+++ /dev/null
@@ -1,14 +0,0 @@
-[package]
-name = "heapsize_derive"
-version = "0.0.0"
-authors = ["David Tolnay <dtolnay@gmail.com>"]
-edition = "2018"
-publish = false
-
-[lib]
-proc-macro = true
-
-[dependencies]
-proc-macro2 = "1.0"
-quote = "1.0"
-syn = { path = "../../.." }
diff --git a/syn/examples/heapsize/heapsize_derive/src/lib.rs b/syn/examples/heapsize/heapsize_derive/src/lib.rs
deleted file mode 100644
index 9176b29..0000000
--- a/syn/examples/heapsize/heapsize_derive/src/lib.rs
+++ /dev/null
@@ -1,96 +0,0 @@
-extern crate proc_macro;
-
-use proc_macro2::TokenStream;
-use quote::{quote, quote_spanned};
-use syn::spanned::Spanned;
-use syn::{parse_macro_input, parse_quote, Data, DeriveInput, Fields, GenericParam, Generics, Index};
-
-#[proc_macro_derive(HeapSize)]
-pub fn derive_heap_size(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
- // Parse the input tokens into a syntax tree.
- let input = parse_macro_input!(input as DeriveInput);
-
- // Used in the quasi-quotation below as `#name`.
- let name = input.ident;
-
- // Add a bound `T: HeapSize` to every type parameter T.
- let generics = add_trait_bounds(input.generics);
- let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
-
- // Generate an expression to sum up the heap size of each field.
- let sum = heap_size_sum(&input.data);
-
- let expanded = quote! {
- // The generated impl.
- impl #impl_generics heapsize::HeapSize for #name #ty_generics #where_clause {
- fn heap_size_of_children(&self) -> usize {
- #sum
- }
- }
- };
-
- // Hand the output tokens back to the compiler.
- proc_macro::TokenStream::from(expanded)
-}
-
-// Add a bound `T: HeapSize` to every type parameter T.
-fn add_trait_bounds(mut generics: Generics) -> Generics {
- for param in &mut generics.params {
- if let GenericParam::Type(ref mut type_param) = *param {
- type_param.bounds.push(parse_quote!(heapsize::HeapSize));
- }
- }
- generics
-}
-
-// Generate an expression to sum up the heap size of each field.
-fn heap_size_sum(data: &Data) -> TokenStream {
- match *data {
- Data::Struct(ref data) => {
- match data.fields {
- Fields::Named(ref fields) => {
- // Expands to an expression like
- //
- // 0 + self.x.heap_size() + self.y.heap_size() + self.z.heap_size()
- //
- // but using fully qualified function call syntax.
- //
- // We take some care to use the span of each `syn::Field` as
- // the span of the corresponding `heap_size_of_children`
- // call. This way if one of the field types does not
- // implement `HeapSize` then the compiler's error message
- // underlines which field it is. An example is shown in the
- // readme of the parent directory.
- let recurse = fields.named.iter().map(|f| {
- let name = &f.ident;
- quote_spanned! {f.span()=>
- heapsize::HeapSize::heap_size_of_children(&self.#name)
- }
- });
- quote! {
- 0 #(+ #recurse)*
- }
- }
- Fields::Unnamed(ref fields) => {
- // Expands to an expression like
- //
- // 0 + self.0.heap_size() + self.1.heap_size() + self.2.heap_size()
- let recurse = fields.unnamed.iter().enumerate().map(|(i, f)| {
- let index = Index::from(i);
- quote_spanned! {f.span()=>
- heapsize::HeapSize::heap_size_of_children(&self.#index)
- }
- });
- quote! {
- 0 #(+ #recurse)*
- }
- }
- Fields::Unit => {
- // Unit structs cannot own more than 0 bytes of heap memory.
- quote!(0)
- }
- }
- }
- Data::Enum(_) | Data::Union(_) => unimplemented!(),
- }
-}
generated by cgit v1.2.1 (git 2.18.0) at 2024-05-17 09:43:07 +0000