# Function __ttest

Source

    pub unsafe fn __ttest() -> u64

🔬This is a nightly-only experimental API. (`stdarch_aarch64_tme` #117216)
Available on (AArch64 or `target_arch="arm64ec"`) and target feature `tme` only.
Expand description

Tests if executing inside a transaction. If no transaction is currently executing, the return value is 0. Otherwise, this intrinsic returns the depth of the transaction.

ARM TME Intrinsics.