md::Value Class Reference

Discriminated union holding one of the JSON-like alternatives (null, bool, signed/unsigned integer, float/double, string, array, or nested object). More...

#include <value.hpp>

Public Types
using	variant_type = std::variant< std::nullptr_t, bool, std::int64_t, std::uint64_t, float, double, std::string, Array, std::unique_ptr< Object > >
	Underlying std::variant type that stores the active alternative.

Public Member Functions
	Value () noexcept
	Construct a null-valued Value.
	Value (Value &&other) noexcept
	Move-construct from another Value, leaving the source in a valid but unspecified state.
Value &	operator= (Value &&other) noexcept
	Move-assign from another Value.
	Value (const Value &other)
	Deep-copy construct from another Value.
Value &	operator= (const Value &other)
	Deep-copy assign from another Value.
	~Value ()
	Destructor.
Value &	operator= (std::initializer_list< Value > il)
	Assign an Array from a braced list of values.
Value &	operator= (std::initializer_list< std::pair< const std::string, Value > > il)
	Assign an Object from a braced list of key/value pairs.
	Value (std::nullptr_t) noexcept
	Construct a null-valued Value.
template<class B > requires std::same_as<B, bool>
	Value (B b) noexcept
	Construct a boolean-valued Value.
template<detail::SignedIntLike T>
	Value (T x) noexcept
	Construct a signed-integer Value (stored as std::int64_t).
template<detail::UnsignedIntLike T>
	Value (T x) noexcept
	Construct an unsigned-integer Value (stored as std::uint64_t).
template<detail::FloatLike T>
	Value (T x) noexcept
	Construct a floating-point Value; float stays float, others widen to double.
	Value (std::string s)
	Construct a string-valued Value from an owning std::string.
	Value (std::string_view s)
	Construct a string-valued Value from a std::string_view.
	Value (const char *s)
	Construct a string-valued Value from a C string.
	Value (Array a)
	Construct an array-valued Value.
	Value (Object o)
	Construct an object-valued Value.
	Value (std::initializer_list< std::pair< const std::string, Value > > il)
	Construct an object-valued Value from a braced list of key/value pairs.
template<class T >
	Value (T *)=delete
	Deleted to prevent silent pointer-to-bool conversions.
bool	is_null () const noexcept
	True if the value holds nullptr.
bool	is_bool () const noexcept
	True if the value holds a bool.
bool	is_int () const noexcept
	True if the value holds a signed integer (std::int64_t).
bool	is_uint () const noexcept
	True if the value holds an unsigned integer (std::uint64_t).
bool	is_float () const noexcept
	True if the value holds a float.
bool	is_double () const noexcept
	True if the value holds a double.
bool	is_number () const noexcept
	True if the value holds any numeric alternative.
bool	is_string () const noexcept
	True if the value holds a std::string.
bool	is_array () const noexcept
	True if the value holds an Array.
bool	is_object () const noexcept
	True if the value holds a nested Object.
bool	as_bool () const
	Return the bool; throws std::bad_variant_access on type mismatch.
std::int64_t	as_int () const
	Return the signed integer; throws on type mismatch.
std::uint64_t	as_uint () const
	Return the unsigned integer; throws on type mismatch.
float	as_float () const
	Return the float; strict — throws if the value isn't a float.
double	as_double () const
	Return as double, widening from int64/uint64/float as needed.
std::string &	as_string ()
	Access the string alternative; throws on type mismatch.
const std::string &	as_string () const
	Access the string alternative; throws on type mismatch.
Array &	as_array ()
	Access the array alternative; throws on type mismatch.
const Array &	as_array () const
	Access the array alternative; throws on type mismatch.
Object &	as_object ()
	Access the nested object; throws on type mismatch.
const Object &	as_object () const
	Access the nested object; throws on type mismatch.
bool *	as_bool_if () noexcept
	Return a pointer to the bool, or nullptr if the value isn't a bool.
const bool *	as_bool_if () const noexcept
	Return a pointer to the bool, or nullptr if the value isn't a bool.
std::int64_t *	as_int_if () noexcept
	Return a pointer to the signed integer, or nullptr if not held.
const std::int64_t *	as_int_if () const noexcept
	Return a pointer to the signed integer, or nullptr if not held.
std::uint64_t *	as_uint_if () noexcept
	Return a pointer to the unsigned integer, or nullptr if not held.
const std::uint64_t *	as_uint_if () const noexcept
	Return a pointer to the unsigned integer, or nullptr if not held.
float *	as_float_if () noexcept
	Return a pointer to the float, or nullptr if not held.
const float *	as_float_if () const noexcept
	Return a pointer to the float, or nullptr if not held.
double *	as_double_if () noexcept
	Return a pointer to the double, or nullptr if not held.
const double *	as_double_if () const noexcept
	Return a pointer to the double, or nullptr if not held.
std::string *	as_string_if () noexcept
	Return a pointer to the string, or nullptr if not held.
const std::string *	as_string_if () const noexcept
	Return a pointer to the string, or nullptr if not held.
Array *	as_array_if () noexcept
	Return a pointer to the array, or nullptr if not held.
const Array *	as_array_if () const noexcept
	Return a pointer to the array, or nullptr if not held.
Object *	as_object_if () noexcept
	Return a pointer to the nested object, or nullptr if not held.
const Object *	as_object_if () const noexcept
	Return a pointer to the nested object, or nullptr if not held.
template<class T >
T *	get_if () noexcept
	Return a pointer to the alternative of type T, or nullptr if not held.
template<class T >
const T *	get_if () const noexcept
	Return a pointer to the alternative of type T, or nullptr if not held.
template<class T >
T	value_or (T fallback) const
	Return the held T by value, or fallback if a different alternative is active.
variant_type &	raw () noexcept
	Return the underlying std::variant for advanced access.
const variant_type &	raw () const noexcept
	Return the underlying std::variant for advanced access.
std::size_t	index () const noexcept
	Return the zero-based index of the active alternative.

Friends
bool	operator== (const Value &a, const Value &b) noexcept
	Deep value-equality compare two Values.
bool	operator!= (const Value &a, const Value &b) noexcept
	Negation of operator==.

Detailed Description

Discriminated union holding one of the JSON-like alternatives (null, bool, signed/unsigned integer, float/double, string, array, or nested object).

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The documentation for this class was generated from the following files:

• include/md/value.hpp
• include/md/object.hpp