# PVv and PEv Helpers

`make_vector<T>(args...)` is a generic variadic-pack-to-`std::vector<T>` constructor (reserving capacity from the argument count up front, then `emplace_back`-ing each argument via a fold expression) - general-purpose plumbing, not specific to parameters. `PV`/`PE` alias [`PTParameterValue`/`PTParameterExpression`](ptparametervalue.md), and `PVv(...)`/`PEv(...)` specialize `make_vector` for each, so a C++ caller building a circuit directly through the [circuit representation API](parseroutput.md) can write something like `PVv(PV("r", 1e3), PV("l", 1e-6))` inline wherever a `std::vector<PTParameterValue>` is expected, instead of constructing and populating one by hand.
