Brazier ORM

Collections

A convenience container that extends std::vector with helper methods for common collection operations — persistence, deletion, JSON serialization, and functional-style querying.

It is designed to work with model classes that follow the brazier ORM conventions (specifically, a static saveMany(...) method and instance methods delete_() / toJson()).

#include <brazier/DB>

Collection inherits all constructors from std::vector<ModelType>, plus a few convenience overloads.

Collection<User> users;

Collection<User> users = { User(...), User(...) };

std::vector<User> vec = ...;
Collection<User> users(vec);
Collection<User> users(std::move(vec));

Persistence

bool save()

Persists the entire collection by delegating to ModelType::saveMany(*this).

Returns true on success, false on failure.

Returns false immediately (without calling saveMany) if the collection is empty.

Collection<User> users;
users.push_back(User("User 1"));
users.push_back(User("User 2"));

if (!users.save()) {
    fail();
}

Note: The exact semantics of saveMany are defined by your model. Collection only forwards the call.

bool delete_()

Deletes every model in the collection by calling item->delete_() on each element.

Iterates over the whole collection, continuing on error.

If an individual delete_() throws, the exception is logged via Logger::log(..., "ERROR") and the loop continues with the next item.

Returns true only if all deletions succeeded; false if the collection is empty or any item failed.

The trailing underscore in delete_ avoids clashing with the C++ keyword delete.

Collection<User> users = User::where("inactive = true");
bool ok = users.delete_();

if (!ok) {
    fail();
}

json toJson() const

Returns a nlohmann::json array where each element is the result of item->toJson().

Collection<User> users = ...;
json j = users.toJson();
std::cout << j.dump(2) << std::endl;

Output:

[
    { "id": 1, "name": "User 1" },
    { "id": 2, "name": "User 2" }
]

Querying

All query methods take a predicate of type std::function<bool(ModelType)> and do not modify the collection.

---

Collection<ModelType> filter(predicate) const

Returns a new Collection containing only the elements for which predicate returns true.

---

auto admins = users.filter([](auto u) { return u->isAdmin(); });

bool all(predicate) const

Returns true if the predicate holds for every element. Returns true for an empty collection (vacuous truth, matching std::all_of).

---

bool everyoneActive = users.all([](auto u) { return u->active; });

bool any(predicate) const

Returns true if the predicate holds for at least one element. Returns false for an empty collection.

---

bool hasAdmin = users.any([](auto u) { return u->isAdmin(); });

ModelType find(predicate) const

Returns the first element matching the predicate, or nullptr if none match.

auto alice = users.find([](auto u) { return u->name == "Alice"; });