common/std-shims/README.md

# `std` shims

`std-shims` is a Rust crate with two purposes:
- Expand the functionality of `core` and `alloc`
- Polyfill functionality only available on newer version of Rust

The goal is to make supporting no-`std` environments, and older versions of
Rust, as simple as possible. For most use cases, replacing `std::` with
`std_shims::` and adding `use std_shims::prelude::*` is sufficient to take full
advantage of `std-shims`.

# API Surface

`std-shims` only aims to have items _mutually available_ between `alloc` (with
extra dependencies) and `std` publicly exposed. Items exclusive to `std`, with
no shims available, will not be exported by `std-shims`.

# Dependencies

`HashSet` and `HashMap` are provided via `hashbrown`. Synchronization
primitives are provided via `spin` (avoiding a requirement on
`critical-section`). Sections of `std::io` are independently matched as
possible. `rustversion` is used to detect when to provide polyfills.

# Disclaimer

No guarantee of one-to-one parity is provided. The shims provided aim to be
sufficient for the average case. Pull requests are _welcome_.
Expose `std_shims::io` on `core` The `io::Write` trait is somewhat worthless, being implemented for nothing, yet `Read` remains fully functional. This also allows using its polyfills _without_ requiring `alloc`. Opportunity taken to make `schnorr-signatures` not require `alloc`. This will require a version bump before being published due to newly requiring the `alloc` feature be specified to maintain pre-existing behavior. Enables resolving https://github.com/monero-oxide/monero-oxide/issues/48. 2025-09-15 21:21:30 -04:00			# `std` shims
Add no_std support to transcript, dalek-ff-group, ed448, ciphersuite, multiexp, schnorr, and monero-generators transcript, dalek-ff-group, ed449, and ciphersuite are all usable with no_std alone. The rest additionally require alloc. Part of #279. 2023-04-22 04:38:47 -04:00
Expose `std_shims::io` on `core` The `io::Write` trait is somewhat worthless, being implemented for nothing, yet `Read` remains fully functional. This also allows using its polyfills _without_ requiring `alloc`. Opportunity taken to make `schnorr-signatures` not require `alloc`. This will require a version bump before being published due to newly requiring the `alloc` feature be specified to maintain pre-existing behavior. Enables resolving https://github.com/monero-oxide/monero-oxide/issues/48. 2025-09-15 21:21:30 -04:00			`std-shims` is a Rust crate with two purposes:
			- Expand the functionality of `core` and `alloc`
			`- Polyfill functionality only available on newer version of Rust`
Add no_std support to transcript, dalek-ff-group, ed448, ciphersuite, multiexp, schnorr, and monero-generators transcript, dalek-ff-group, ed449, and ciphersuite are all usable with no_std alone. The rest additionally require alloc. Part of #279. 2023-04-22 04:38:47 -04:00
Expose `std_shims::io` on `core` The `io::Write` trait is somewhat worthless, being implemented for nothing, yet `Read` remains fully functional. This also allows using its polyfills _without_ requiring `alloc`. Opportunity taken to make `schnorr-signatures` not require `alloc`. This will require a version bump before being published due to newly requiring the `alloc` feature be specified to maintain pre-existing behavior. Enables resolving https://github.com/monero-oxide/monero-oxide/issues/48. 2025-09-15 21:21:30 -04:00			The goal is to make supporting no-`std` environments, and older versions of
			Rust, as simple as possible. For most use cases, replacing `std::` with
			`std_shims::` and adding `use std_shims::prelude::*` is sufficient to take full
			advantage of `std-shims`.
Expose Once within std-shims, bump spin to 0.9 This is technically a semver break due to bumping spin to 0.10, with the types from spin being directly exposed. Long-term, we should not directly expose spin but instead have our own types which are thin wrappers around spin (clearly defining our API and allowing upgrading internals without breaking semver). 2025-08-19 13:36:01 -04:00
Expose `std_shims::io` on `core` The `io::Write` trait is somewhat worthless, being implemented for nothing, yet `Read` remains fully functional. This also allows using its polyfills _without_ requiring `alloc`. Opportunity taken to make `schnorr-signatures` not require `alloc`. This will require a version bump before being published due to newly requiring the `alloc` feature be specified to maintain pre-existing behavior. Enables resolving https://github.com/monero-oxide/monero-oxide/issues/48. 2025-09-15 21:21:30 -04:00			`# API Surface`

			`std-shims` only aims to have items _mutually available_ between `alloc` (with
			extra dependencies) and `std` publicly exposed. Items exclusive to `std`, with
			no shims available, will not be exported by `std-shims`.

			`# Dependencies`

			`HashSet` and `HashMap` are provided via `hashbrown`. Synchronization
			primitives are provided via `spin` (avoiding a requirement on
			`critical-section`). Sections of `std::io` are independently matched as
			possible. `rustversion` is used to detect when to provide polyfills.

			`# Disclaimer`

			`No guarantee of one-to-one parity is provided. The shims provided aim to be`
			`sufficient for the average case. Pull requests are _welcome_.`