{"ast_node_type":"other","tokens":[{"end":5,"kind":"keyword","start":0,"text":"{"}]}
    {
        F: rustc_apfloat::Float + rustc_apfloat::FloatConvert<F> + Into<Scalar<M::Provenance>>,
        let x: F = self.read_scalar(&args[0])?.to_float()?;