Enum InstanceRepr 

pub enum InstanceRepr {
    Complete,
    Args(Vec<InstanceArg>),
    Unrecorded(&'static str),
}

How much of a value’s type its own payload determines.

Variants

Complete

The descriptor is the whole answer: every scalar, Unit, BitSet.

Args(Vec<InstanceArg>)

The type takes arguments, and these are what the payload records, in the order the type spells them (Map[K, V] yields key then value).

Unrecorded(&'static str)

The value’s type is not recoverable from the value. The string says why, and is what a NoRuntimeRepr reports.