cosmos::CosmosError Class Reference

Base class for libcosmos exceptions. More...

#include <CosmosError.hxx>

Inheritance diagram for cosmos::CosmosError:

Public Member Functions
	CosmosError (const std::string_view error_class, const std::string_view fixed_text={})
CosmosError &	setInfo (const char *file, const size_t line, const char *func)
	Set exception context information.
const char *	what () const override throw ()
	Implementation of the std::exception interface.
std::string	shortWhat () const
	Returns a shorter description of the error without verbose context.
virtual void	raise ()=0
	Throw the most specialized type of this object in the inheritance hierarchy.

Protected Member Functions
virtual void	generateMsg () const
	Append type specific error information to m_msg.
void	setErrorClass (const std::string_view error_class)
	Allows to override error class to allow simpler implementation of derived types.

Protected Attributes
std::string_view	m_error_class
	Descriptive, unique error class label.
std::string	m_msg
	Runtime generated error message.
bool	m_msg_generated = false
	Whether m_msg has been assembled yet.
const char *	m_file = nullptr
const char *	m_func = nullptr
size_t	m_line = 0

Detailed Description

Base class for libcosmos exceptions.

This base class carries the file, line and function contextual information from where it was thrown. Furthermore it stores a dynamically allocated string with optional additional runtime information.

The cosmos_throw macro allows to transparently throw any type derived from this base class, all contextual information filled in.

Each derived type must override the raise() virtual function to allow to throw the correct specialized type even when only the base class type is known. The generateMsg() function can be overwritten to update the error message content at the time what() is called. This allows to defer expensive calculations until the time the actual exception message content is accessed.

Definition at line 74 of file CosmosError.hxx.

Constructor & Destructor Documentation

CosmosError()

cosmos::CosmosError::CosmosError ( const std::string_view error_class, const std::string_view fixed_text = {} )

inlineexplicit

Definition at line 78 of file CosmosError.hxx.

                                                                                                 {}) :
                        m_error_class{error_class} {
                m_msg = fixed_text;
        }

Member Function Documentation

generateMsg()

virtual void cosmos::CosmosError::generateMsg ( ) const

inlineprotectedvirtual

Append type specific error information to m_msg.

This function is called by the implementation when error specific information needs to be appended to the m_msg string.

At entry into this function m_msg can already contain data that must not be discarded.

This function will be called at most once during the lifetime of an object, and only if the error message actually needs to be generated due to a call to what().

Reimplemented in cosmos::ApiError, cosmos::FileError, and cosmos::ResolveError.

Definition at line 125 of file CosmosError.hxx.

{};

setErrorClass()

void cosmos::CosmosError::setErrorClass ( const std::string_view error_class )

inlineprotected

Allows to override error class to allow simpler implementation of derived types.

Definition at line 128 of file CosmosError.hxx.

                                                             {
                m_error_class = error_class;
        }

setInfo()

CosmosError & cosmos::CosmosError::setInfo ( const char * file, const size_t line, const char * func )

inline

Set exception context information.

This function is used by the cosmos_throw macro to store information about the program location where the exception was thrown.

Definition at line 89 of file CosmosError.hxx.

                                                                                    {
                m_line = line;
                m_file = file;
                m_func = func;
 
                return *this;
        }

shortWhat()

std::string cosmos::CosmosError::shortWhat

(

)

const

Returns a shorter description of the error without verbose context.

Definition at line 24 of file CosmosError.cxx.

                                       {
        const std::string_view what{this->what()};
 
        const auto start = what.find(m_error_class) + m_error_class.size() + 2;
 
        return std::string{what.substr(start)};
}

what()

const char * cosmos::CosmosError::what ( ) const throw (  )

override

Implementation of the std::exception interface.

Returns a completely formatted message describing this error instance. The returned string is only valid for the lifetime of this object.

Definition at line 9 of file CosmosError.cxx.

                                            {
        if (!m_msg_generated) {
                auto orig = m_msg;
                std::stringstream ss;
                ss << m_file << ":" << m_line << " [" << m_func << "]: "
                        << m_error_class << ": ";
                m_msg = ss.str();
                m_msg += orig;
                generateMsg();
                m_msg_generated = true;
        }
 
        return m_msg.c_str();
}

Member Data Documentation

m_error_class

std::string_view cosmos::CosmosError::m_error_class

protected

Descriptive, unique error class label.

Definition at line 135 of file CosmosError.hxx.

m_file

const char* cosmos::CosmosError::m_file = nullptr

protected

Definition at line 140 of file CosmosError.hxx.

m_func

const char* cosmos::CosmosError::m_func = nullptr

protected

Definition at line 141 of file CosmosError.hxx.

m_line

size_t cosmos::CosmosError::m_line = 0

protected

Definition at line 142 of file CosmosError.hxx.

m_msg

std::string cosmos::CosmosError::m_msg

mutableprotected

Runtime generated error message.

Definition at line 137 of file CosmosError.hxx.

m_msg_generated

bool cosmos::CosmosError::m_msg_generated = false

mutableprotected

Whether m_msg has been assembled yet.

Definition at line 139 of file CosmosError.hxx.

---

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

• include/error/CosmosError.hxx
• src/error/CosmosError.cxx