by::tres< T, R > Class Template Reference

Template result container with typed error information. More...

#include <tres.hpp>

Inheritance diagram for by::tres< T, R >:

Public Member Functions
	tres (const T &value)
	tres (const R &value)
R &	getErr ()
	Gets the contained error.
const R &	getErr () const BY_CONST_FUNC(getErr()) void rel() override
	Releases/clears both the contained value and the error, making the instance empty.
void	set (const T &arg) override
	Sets the contained value and clears any existing error.
void	setErr (const R &arg)
	Sets the contained error and clears any existing value.
Public Member Functions inherited from by::tmay< T >
	tmay (const T &value)
	tmay (const tmedium< T > &value)
T *	operator-> ()
const T *	operator-> () const BY_CONST_FUNC(operator->())
T &	operator* ()
const T &	operator* () const BY_CONST_FUNC(operator*())
	operator T& ()
	operator const T & () const
	operator nbool () const
nbool	has () const
T *	get ()
	Gets the contained value.
const T *	get () const BY_CONST_FUNC(get()) virtual void rel()
	Releases/clears the contained value, making the instance empty.

Detailed Description

template<typename T, typename R>
class by::tres< T, R >

Template result container with typed error information.

Identical to tmay but allows defining a custom error type when errors occur. While tmay<T> can only indicate whether an error occurred or not, tres<T, R> can provide detailed error information of type R when an error occurs.

Usage

Example comparing tmay and tres:

// Using tmay - can only tell if error occurred:
tmay<int> result1 = parseNumber("abc");
if(!result1.has()) {
    // Know there's an error, but not what kind
}
 
// Using tres - can get error details:
tres<int, std::string> result2 = parseNumber("abc");
if(!result2.has()) {
    std::string errorMsg = result2.getErr(); // Get specific error message
    BY_E("Parse failed: %s", errorMsg.c_str());
}

Common error types include std::string for error messages, or custom error enums for categorized error handling.

Member Function Documentation

getErr()

template<typename T , typename R >

R & by::tres< T, R >::getErr

(

)

Gets the contained error.

Warning

Should only be called when has() returns false. Accessing when has() is true results in undefined behavior.

Returns

A reference to the contained error object.

set()

template<typename T , typename R >

void by::tres< T, R >::set ( const T & arg )

overridevirtual

Sets the contained value and clears any existing error.

Reimplemented from by::tmay< T >.

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

• /home/runner/work/stela/stela/module/indep/helper/tres.hpp