[CONSTRUCTOR]
Exception(
const fcf::Exception& a_exception)
[CONSTRUCTOR]
Exception(
const fcf::Exception& a_exception,
bool a_copySub)
template <typename ...TArgPack>
[CONSTRUCTOR]
Exception(
const char* a_file,
unsigned int a_line,
const TArgPack&... a_argPack)
template <typename ...TArgPack>
[CONSTRUCTOR]
Exception(
const char* a_shortMessage,
const char* a_patternMessage,
const char* a_file,
unsigned int a_line,
const TArgPack&... a_argPack)
template <typename ...TArgPack>
[CONSTRUCTOR]
Exception(
const fcf::Exception& a_subException,
const char* a_file,
unsigned int a_line,
const TArgPack&... a_argPack)
template <typename ...TArgPack>
[CONSTRUCTOR]
Exception(
const fcf::Exception& a_subException,
const char* a_shortMessage,
const char* a_patternMessage,
const char* a_file,
unsigned int a_line,
const TArgPack&... a_argPack)
Class: fcf::Exception
Package: fcfBasis
File:
bits/PartException/ExceptionDecl.hpp
(
link_to_the_declaration_in_the_file
)
Implementation file:
bits/PartException/Exception.hpp
(
link_to_the_implementation_in_the_file
)
Available from version: 1.0.1
Initializes a new instance of the fcf::Exception class. Depending on the arguments provided, it can create a simple error, an error with an associated exception object, or a complex exception with formatted messages and arguments.
The fcf::Exception class provides a robust mechanism for error reporting and exception handling. Its constructors allow for various levels of detail, enabling developers to provide rich context during error propagation:
- Constructor without parameters: Creates an exception object without information; in this case, the name() method returns an empty string.
- Constructor without exception name: If a constructor is used without specifying a_shortMessage, an exception with the name "FCF_EXCEPTION" is created, and the message pattern is set to "${{1}}$" (i.e., it outputs the first passed argument TArgPack)
- Wrapped Mode: Allows the creation of an exception that wraps an existing fcf::Exception object (if the a_subexception parameter is passed). This is useful for maintaining a chain of causality where one error leads to another.
- Formatted Mode (Template): The most powerful constructor. It accepts a message pattern (using
${{1}}$, ${{2}}$, etc.) and a variadic pack of arguments. This allows for highly dynamic and informative error messages that are formatted only when the message is actually requested.
Arguments
const char* a_file
- The file name where the exception occurred.
unsigned int a_line
- The line number where the exception occurred.
const TArgPack&... a_argPack
- Variadic arguments used to substitute placeholders (e.g., ${{1}}$) in the error message pattern.
const fcf::Exception& a_exception
- The existing fcf::Exception object to be wrapped.
bool a_copySub = true
- Flag indicating whether the sub-exceptions of the wrapped exception should also be copied. If the parameter is not specified, it defaults to true.
const char* a_shortMessage
- A custom short message for the exception.
const char* a_patternMessage
- A message pattern containing placeholders (e.g., ${{1}}$) that will be filled by the provided arguments.
const fcf::Exception& a_subException
- The base fcf::Exception object used to create a new exception with additional context.
Example: Demonstrating various constructor overloads
An example showing the use of the default constructor, the template constructor for formatted messages, and how to catch and inspect the resulting exception.
#include <iostream>
#define FCF_BASIS_IMPLEMENTATION
#include <fcfBasis/basis.hpp>
int main(int argc, char* argv[]) {
// 1. Constructor with custom message and arguments (Template Mode)
// The arguments "Arg1" and 42 will be used to fill the pattern ${{1}}$ and ${{2}}$
fcf::Exception ex2("Custom Error", "Message: ${{1}}$ and ${{2}}$", __FILE__, __LINE__, "Arg1", 42);
// 2. Throwing the exception and catching it to verify the output
try {
std::cout << "Throwing exception..." << std::endl;
throw ex2;
} catch (const fcf::Exception& e) {
// Accessing the formatted message and position
std::cout << "Caught: " << e.message() << std::endl;
std::cout << "Position: " << e.position() << std::endl;
}
return 0;
}
Output:
Throwing exception...
Caught: Message: Arg1 and 42
Position: /home/user/application/main.cpp:8
The fcf::Exception constructors allow for flexible and detailed error reporting, from simple flags to complex, argument-driven messages.
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