Method erase_if

lib/programmemory.cpp:192–206

}

void ProgramMemory::erase_if(const std::function<bool(const ExprIdToken&)>& pred)
{
    if (mValues->empty())
        return;

    // TODO: how to delay until we actually modify?
    copyOnWrite();

    for (auto it = mValues->begin(); it != mValues->end();) {
        if (pred(it->first))
            it = mValues->erase(it);
        else
            ++it;
    }
}

void ProgramMemory::swap(ProgramMemory &pm) noexcept
{