Configure Rust

Using the right toolchain for TFHE-rs.

TFHE-rs only requires a nightly toolchain for building the C API and using advanced SIMD instructions, otherwise you can use a stable toolchain (with version >= 1.72) Install the needed Rust toolchain:

# If you don't need the C API or the advanced still unstable SIMD instructions use this
rustup toolchain install stable
# Otherwise install a nightly toolchain
rustup toolchain install nightly

Then, you can either:

• Manually specify the toolchain to use in each of the cargo commands:

# By default the +stable should not be needed, but we add it here for completeness
cargo +stable build
cargo +stable test
# Or
cargo +nightly build
cargo +nightly test

• Or override the toolchain to use for the current project:

# This should not be necessary by default, but if you want to make sure your configuration is
# correct you can still set the overridden toolchain to stable
rustup override set stable
# cargo will use the `stable` toolchain.
cargo build
# Or
rustup override set nightly
# cargo will use the `nightly` toolchain.
cargo build

To check the toolchain that Cargo will use by default, you can use the following command:

rustup show

Choosing your features

TFHE-rs exposes different cargo features to customize the types and features used.

Homomorphic Types.

This crate exposes two kinds of data types. Each kind is enabled by activating its corresponding feature in the TOML line. Each kind may have multiple types:

Kind	Features	Type(s)
Booleans	boolean	Booleans
ShortInts	shortint	Short integers
Integers	integer	Arbitrary-sized integers

AVX-512

In general, the library automatically chooses the best instruction sets available by the host. However, in the case of 'AVX-512', this has to be explicitly chosen as a feature. This requires to use a nightly toolchain along with the feature nightly-avx512.

cargo +nightly build --features=nightly-avx512