Validations::byLedger

Iterate the set of validations associated with a given ledger id.

template<
    class Pre,
    class F>
void
byLedger(
    ScopedLock const&,
    ID const& ledgerID,
    Pre&& pre,
    F&& f);

Name	Description
`lock`	Existing lock on mutex_
`ledgerID`	The identifier of the ledger
`pre`	Invokable with signature(std::size_t)
`f`	Invokable with signature (NodeKey const &, Validation const &)

The invokable pre is called prior to iterating validations. The argument is the number of times f will be called.

The invokable f is expected to be a simple transformation of its arguments and will be called with mutex_ under lock.