NavState Class Reference

A generic, type-safe, lock-free 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 function.

Public Member Functions
std::string	debug_string () const
	Dumps all keys and their values to a formatted string.
template<typename T>
const T &	get (const std::string &key) const
	Retrieves a const reference to the value of type T associated with the given key.
bool	has (const std::string &key) const
	Checks whether a key exists in the NavState.
	NavState ()
	Constructs an empty NavState and registers basic type printers.
template<typename T>
void	set (const std::string &key, const T &value)
	Stores a value of type T associated with the given key.
virtual	~NavState ()=default
	Destructor.

Static Public Member Functions
static void	print_stacktrace ()
	Prints the current C++ stack trace to standard error.
static void	register_basic_printers ()
	Registers default string printers for basic types: int, float, double, std::string, bool, char.
template<typename T>
static void	register_printer (std::function< std::string(const T &)> printer)
	Registers a printer for a given type.

Detailed Description

A generic, type-safe, lock-free 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 raw, shared, and copy-based insertion.
• Debug utilities including stack trace and introspection.

Example usage:

NavState state;
state.set("goal_reached", false);
bool reached = state.get<bool>("goal_reached");

Member Typedef Documentation

AnyPrinter

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

Type alias for a generic printer function.

Used to print debug output for stored values.

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

Dumps all keys and their values to a formatted string.

If a printer is registered for a given type, it is used; otherwise, the raw pointer address and hash are shown.

Returns

String representation of current state.

get()

template<typename T>

const T & get

(

const std::string &

key

)

const

Retrieves a const reference to the value of type T associated with the given key.

The reference points to the value managed internally through a shared_ptr<T>. This avoids unnecessary copies, but care must be taken not to hold the reference beyond the lifetime of the NavState instance.

Template Parameters

T	The expected type of the stored value.

Parameters

key	The key of the value to retrieve.

Returns

const T& A const reference to the stored value.

Exceptions

std::runtime_error

if the key is not found or there is a type mismatch.

has()

bool has

(

const std::string &

key

)

const

Checks whether a key exists in the NavState.

Parameters

key	Lookup key.

Returns

True if the key is registered.

print_stacktrace()

static void print_stacktrace ( )

static

Prints the current C++ stack trace to standard error.

Used to assist debugging in exception contexts.

register_basic_printers()

static void register_basic_printers ( )

static

Registers default string printers for basic types: 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 printer for a given type.

The function will be used to convert values of this type into strings for use in debug_string().

Template Parameters

T	Type to register.

Parameters

printer

Function that converts a const reference to string.

set()

template<typename T>

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

Stores a value of type T associated with the given key.

If the key does not exist, a new shared_ptr<T> is created and stored. If the key already exists, the stored value is updated in-place.

The value is internally managed through a shared_ptr<T>.

Template Parameters

T	The type of the value to store. Must be copy-assignable.

Parameters

key	The key associated with the value.
value	The value to store.

Exceptions

std::runtime_error

if there is a type mismatch with an existing key.

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

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