responses.md

Query Responses

Value Types

As the comment in GraphQLResponse.h says, GraphQL responses are not technically JSON-specific, although that is probably the most common way of representing them. These are the primitive types that may be represented in GraphQL, as of the October 2021 spec:

enum class [[nodiscard("unnecessary conversion")]] Type : std::uint8_t {
	Map,	   // JSON Object
	List,	   // JSON Array
	String,	   // JSON String
	Null,	   // JSON null
	Boolean,   // JSON true or false
	Int,	   // JSON Number
	Float,	   // JSON Number
	EnumValue, // JSON String
	ID,		   // JSON String
	Scalar,	   // JSON any type
};

Common Accessors

Anywhere that a GraphQL result, a scalar type, or a GraphQL value literal is used, it's represented in cppgraphqlgen using an instance of graphql::response::Value. These can be constructed with any of the types in the graphql::response::Type enum, and depending on the type with which they are initialized, different accessors will be enabled.

Every type implements specializations for some subset of get() which does not allocate any memory, set(...) which takes an r-value, and release() which transfers ownership along with any extra allocations to the caller. Which of these methods are supported and what C++ types they use are determined by the ValueTypeTraits<ValueType> template and its specializations.

Map and List

Map and List types enable collection methods like reserve(size_t), size(), and emplace_back(...). Map additionally implements begin() and end() for range-based for loops and find(const std::string&) and operator[](const std::string&) for key-based lookups. List has an operator[](size_t) for index-based instead of key-based lookups.