# Int64.From

Last updated: 2026-09-09

Convert an integer to signed 64-bit int64 with a range check.

Built into Yeho; no import is needed. These additions have Windows CPU-oracle developer-host evidence. Kyber rejects these operations; this does not qualify Starfish or other targets.

`Int64.From(integer value) -> int64`

Out-of-range values throw Error with type integer.range. No wrapping or clamping; bool, float and text are rejected.

Contract and host execution evidence: yeho/docs/runtime/hardware-host-tools.md. This small example was type checked, not executed.

## Parameters

- value (integer): An integer value in signed 64-bit range.

## Type-checked example

```yeho
int64 value = Int64.From(42)
```

project.mech:

```toml
manifestVersion = "2"
package = "api.example.runtime__int64_from"
version = "0.1.0"
languageEdition = "yeho-core-2026.1"

[app]
kind = "headless"
```

Source: yeho/src/compiler/common/intrinsic_registry.cpp:802