tec::Json Struct Reference

Utility class for generating minimal, valid JSON strings at compile-time and runtime. More...

#include <tec_json.hpp>

Public Member Functions
template<typename T >
std::string	operator() (const T &val, const char *name)
	Functor interface — serialize with explicit name.
template<typename T >
std::string	operator() (const T &val)
	Functor interface — serialize without name (root value).

Static Public Member Functions
static void	print_name (std::ostringstream &os, const char *name)
	Helper to optionally emit a JSON key name.
static std::string	json (const std::string &val, const char *name=nullptr)
	Serialize a std::string as a JSON string literal.
static std::string	json (const Blob &val, const char *name=nullptr)
	Serialize a Blob object as a base64-encoded JSON string.
static std::string	json_bool (const bool &val, const char *name=nullptr)
	Serialize a boolean as JSON true or false.
template<typename TContainer >
static std::string	json_container (const TContainer &c, const char *name)
	Serialize any container (with .begin()/.end()) as a JSON array.
template<typename TMap >
static std::string	json_map (const TMap &m, const char *name)
	Serialize unordered map-like containers as JSON objects.
template<typename TObject >
static std::string	json_object (const TObject &obj, const char *name)
	Serialize a tec::Serializable-derived object as a nested JSON object.
template<typename T >
static std::string	json (const T &val, const char *name)
	Generic JSON serializer with automatic type dispatching.

Static Public Attributes
static constexpr char	sep [] {", "}
	Separator used between array/object elements.
static constexpr char	infix [] {": "}
	Separator used between object key and value.

Detailed Description

Utility class for generating minimal, valid JSON strings at compile-time and runtime.

Json provides a lightweight, header-only way to convert basic C++ types, containers, and tec::Serializable objects into JSON-formatted strings.

It is intentionally minimal — no external dependencies, no parsing, only serialization. The output is valid JSON but not pretty-printed (compact form).

Supports:

• Fundamental types (int, float, bool, etc.)
• std::string
• tec::Blob (as Base64-encoded string)
• Any type satisfying is_container_v<T> → JSON array
• Any type satisfying is_map_v<T> → JSON object
• Any type derived from tec::JsonSerializable → nested object via to_json()

Note

This is not a full JSON library — it's designed for debugging, logging, network messages, and configuration where performance and simplicity matter.

struct Person: tec::Serializable {
    using json = tec::Json;
    static constexpr auto sep{tec::Json::sep};
 
    short age;
    std::string name;
    std::string surname;
 
    friend std::ostream& operator << (std::ostream& os, const Person& p) {
        os << json{}(p);
        return os;
    }
 
    std::string to_json() const override {
        std::ostringstream os;
        os
            << json{}(age, "age") << sep
            << json{}(name, "name") << sep
            << json{}(surname, "surname")
            ;
        return os.str();
    }
};

Member Function Documentation

json() [1/3]

static std::string tec::Json::json ( const Blob &  val, const char *  name = nullptr  )

inlinestatic

Serialize a Blob object as a base64-encoded JSON string.

Parameters

val	The byte container
name	Optional JSON key name

Returns

Base64-encoded string

json() [2/3]

static std::string tec::Json::json ( const std::string &  val, const char *  name = nullptr  )

inlinestatic

Serialize a std::string as a JSON string literal.

Parameters

val	The string value
name	Optional JSON key name

Returns

JSON fragment (with optional key)

json() [3/3]

template<typename T >

static std::string tec::Json::json ( const T &  val, const char *  name  )

inlinestatic

Generic JSON serializer with automatic type dispatching.

Dispatches to the most appropriate specialization based on type traits:

1. tec::Serializable → json_object()
2. Unordered map-like → json_map()
3. Container → json_container()
4. Scalar types → direct operator<<

Template Parameters

T	Value type

Parameters

val	Value to serialize
name	Optional JSON key name

Returns

JSON fragment

json_bool()

static std::string tec::Json::json_bool ( const bool &  val, const char *  name = nullptr  )

inlinestatic

Serialize a boolean as JSON true or false.

Parameters

val	The boolean value
name	Optional JSON key name

Returns

JSON boolean literal

json_container()

template<typename TContainer >

static std::string tec::Json::json_container ( const TContainer &  c, const char *  name  )

inlinestatic

Serialize any container (with .begin()/.end()) as a JSON array.

Elements are serialized using their own operator<< (or specialized json() if available).

Template Parameters

TContainer

Container type satisfying is_container_v

Parameters

c	Container instance
name	Optional array name (e.g., "myArray": [...])

Returns

JSON array string

json_map()

template<typename TMap >

static std::string tec::Json::json_map ( const TMap &  m, const char *  name  )

inlinestatic

Serialize unordered map-like containers as JSON objects.

Keys and values must support operator<<. Structured bindings are used for iteration.

Template Parameters

TMap	Map type satisfying is_map_v

Parameters

m	Map instance
name	Optional object name

Returns

JSON object string

json_object()

template<typename TObject >

static std::string tec::Json::json_object ( const TObject &  obj, const char *  name  )

inlinestatic

Serialize a tec::Serializable-derived object as a nested JSON object.

Calls the object's to_json() method and wraps it in braces.

Template Parameters

TObject

Type derived from tec::Serializable

Parameters

obj	Object instance
name	Optional field name

Returns

JSON like "name": { ...to_json output... }

operator()() [1/2]

template<typename T >

std::string tec::Json::operator() ( const T &  val )

inline

Functor interface — serialize without name (root value).

Allows usage like: Json{}(myValue)

Template Parameters

T	Value type

Parameters

val	Value to serialize

Returns

JSON string (no key prefix)

operator()() [2/2]

template<typename T >

std::string tec::Json::operator() ( const T &  val, const char *  name  )

inline

Functor interface — serialize with explicit name.

Allows usage like: Json{}(myValue, "fieldName")

Template Parameters

T	Value type

Parameters

val	Value to serialize
name	Field name in JSON

Returns

JSON string

print_name()

static void tec::Json::print_name ( std::ostringstream &  os, const char *  name  )

inlinestatic

Helper to optionally emit a JSON key name.

If name is non-null, outputs "name": (with proper quoting and spacing). If name is null, does nothing.

Parameters

os	Output stream to write to
name	Optional field name (null-terminated string)

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The documentation for this struct was generated from the following file:

• tec_json.hpp