Add collections crate

Cargo.toml

@@ -1,6 +1,7 @@
 [workspace]
 resolver = "2"
 members = [
+  "collections",
   "discriminator",
   "discriminator-derive",
   "discriminator-syn",

collections/Cargo.toml

@@ -0,0 +1,29 @@
+[package]
+name = "spl-collections"
+version = "0.0.0"
+description = "Serialization-aware collection wrappers for Solana account data"
+authors = ["Anza Maintainers <maintainers@anza.xyz>"]
+repository = "https://github.com/solana-program/libraries"
+license = "Apache-2.0"
+edition = "2021"
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+all-features = true
+rustdoc-args = ["--cfg=docsrs"]
+
+[features]
+alloc = []
+borsh = ["dep:borsh", "alloc"]
+default = ["alloc"]
+wincode = ["dep:wincode", "alloc"]
+
+[dependencies]
+borsh = { version = "1.0", features = ["derive"], default-features = false, optional = true }
+wincode = { version = "0.4.4", features = ["alloc", "derive"], default-features = false, optional = true }
+
+[dev-dependencies]
+spl-collections = { path = ".", features = ["borsh", "wincode"] }
+
+[lib]
+crate-type = ["lib"]

collections/src/lib.rs

@@ -0,0 +1,21 @@
+//! Serialization-aware collection wrappers for Solana account data.
+//!
+//! This crate provides wrappers around collection types to support custom serialization
+//! logic. This is useful for programs that have specific requirements for how data is
+//! stored.
+
+#![no_std]
+#![cfg_attr(docsrs, feature(doc_cfg))]
+
+#[cfg(feature = "alloc")]
+extern crate alloc;
+
+#[cfg(feature = "alloc")]
+mod string;
+#[cfg(feature = "alloc")]
+mod vec;
+
+#[cfg(feature = "alloc")]
+pub use string::*;
+#[cfg(feature = "alloc")]
+pub use vec::*;