NavState Class Reference

A generic, type-safe, thread-safe blackboard to hold runtime state. More...

#include <NavState.hpp>

Public Types
using	AnyPrinter = std::function<std::string(std::shared_ptr<void>)>
	Type alias for a generic printer functor used by debug_string().

Public Member Functions
std::string	debug_string () const
	Generates a human-readable dump of all stored keys and values.
template<typename T>
const T &	get (const std::string &key) const
	Retrieves a const reference to the stored value of type T for key.
template<typename T>
const std::shared_ptr< T >	get_ptr (const std::string &key) const
	Retrieves the shared_ptr to the stored value of type T for key.
bool	has (const std::string &key) const
	Checks whether key exists in the state.
	NavState ()
	Constructs an empty NavState and registers basic type printers.
template<typename T>
void	set (const std::string &key, const std::shared_ptr< T > value_ptr)
	Stores a value of type T associated with key (by shared pointer).
template<typename T>
void	set (const std::string &key, const T &value)
	Stores a value of type T associated with key (by copy).
virtual	~NavState ()=default
	Destructor.

Static Public Member Functions
static void	print_stacktrace ()
	Prints the current C++ stack trace to std::cerr.
static void	register_basic_printers ()
	Registers default printers for common scalar types.
template<typename T>
static void	register_printer (std::function< std::string(const T &)> printer)
	Registers a pretty-printer for type T used by debug_string().

Detailed Description

A generic, type-safe, thread-safe blackboard to hold runtime state.

NavState provides:

• Type-erased storage using std::shared_ptr<void>.
• Runtime type verification and safe casting via typeid.
• Support for value-based and shared-pointer-based insertion.
• Debug utilities including stack trace and introspection.

Note

Thread-safety is enforced with an internal std::mutex.

Member Typedef Documentation

AnyPrinter

using AnyPrinter = std::function<std::string(std::shared_ptr<void>)>

Type alias for a generic printer functor used by debug_string().

The functor receives the stored value as a std::shared_ptr<void> and returns a string representation.

Constructor & Destructor Documentation

NavState()

NavState

(

)

Constructs an empty NavState and registers basic type printers.

~NavState()

virtual ~NavState ( )

virtualdefault

Destructor.

Member Function Documentation

debug_string()

std::string debug_string

(

)

const

Generates a human-readable dump of all stored keys and values.

For types with registered printers, their printer is used; otherwise, the raw pointer address and type hash are shown.

Returns

Multi-line string with one entry per key.

get()

template<typename T>

const T & get

(

const std::string &

key

)

const

Retrieves a const reference to the stored value of type T for key.

The reference refers to the object managed by the internal std::shared_ptr<T>.

Template Parameters

T	Expected stored type.

Parameters

key	Key to retrieve.

Returns

Const reference to the stored T.

Exceptions

std::runtime_error

If key is missing or the stored type does not match T.

get_ptr()

template<typename T>

const std::shared_ptr< T > get_ptr

(

const std::string &

key

)

const

Retrieves the shared_ptr to the stored value of type T for key.

The pointer refers to the object managed by the internal std::shared_ptr<T>.

Template Parameters

T	Expected stored type.

Parameters

key	Key to retrieve.

Returns

shared_ptr to the stored T.

Exceptions

std::runtime_error

If key is missing or the stored type does not match T.

has()

bool has

(

const std::string &

key

)

const

Checks whether key exists in the state.

Parameters

key	Key to query.

Returns

true if present, otherwise false.

print_stacktrace()

static void print_stacktrace ( )

static

Prints the current C++ stack trace to std::cerr.

Note

Intended for debugging in exception contexts.

register_basic_printers()

static void register_basic_printers ( )

static

Registers default printers for common scalar types.

Registers printers for: int, float, double, std::string, bool, char.

register_printer()

template<typename T>

static void register_printer ( std::function< std::string(const T &)> printer )

static

Registers a pretty-printer for type T used by debug_string().

Template Parameters

T	Type to register.

Parameters

printer

Functor that renders const T& to a string.

set() [1/2]

template<typename T>

void set	(	const std::string &	key,
		const std::shared_ptr< T >	value_ptr )

Stores a value of type T associated with key (by shared pointer).

If key does not exist, value_ptr is stored directly. If key exists, the stored std::shared_ptr<T> is replaced by value_ptr.

Template Parameters

T	Value type.

Parameters

key	Key associated with the value.
value_ptr	Shared pointer to the value to store.

Exceptions

std::runtime_error

If key exists with a different stored type; includes a stack trace.

set() [2/2]

template<typename T>

void set	(	const std::string &	key,
		const T &	value )

Stores a value of type T associated with key (by copy).

If key does not exist, a new std::shared_ptr<T> is created and stored. If key exists, the stored value is overwritten in place.

Template Parameters

T	Value type. Must be copy-assignable.

Parameters

key	Key associated with the value.
value	Value to store (copied into internal storage).

Exceptions

std::runtime_error

If key exists with a different stored type; includes a stack trace.

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

• easynav_common/include/easynav_common/types/NavState.hpp