pub unsafe extern "C" fn weld_value_context(value: weld_value_t) -> weld_context_t {
    let value = value as *mut weld::WeldValue;
    let value = &*value;
    if let Some(context) = value.context() {
        Box::into_raw(Box::new(context)) as _
    } else {
        ptr::null_mut() as _
    }
}
Returns the context of a value.

Since contexts are internally reference-counted, this function increases the reference count of
the context. The context must be freed with `weld_context_free` to decrement the internal
reference count. Since Weld values owned by a context internally hold a reference to the
context, the value is guaranteed to be live until `weld_value_free` is called.
weld-capi/src/lib.rs