Error.h File Reference

#include "CoreMinimal.h"
#include "Mcro/Error.Fwd.h"
#include "Void.h"
#include "Mcro/Types.h"
#include "Mcro/Concepts.h"
#include "Mcro/SharedObjects.h"
#include "Mcro/Observable.Fwd.h"
#include "Mcro/TextMacros.h"
#include "Mcro/Text.h"
#include "Mcro/Delegates/EventDelegate.h"
#include "Mcro/LibraryIncludes/Start.h"
#include "yaml-cpp/yaml.h"
#include "Mcro/LibraryIncludes/End.h"
#include <source_location>

Go to the source code of this file.

Data Structures
class	Mcro::Error::IError
	A base class for a structured error handling and reporting with modular architecture and fluent API. More...
class	Mcro::Error::FAssertion
	A simple error type for checking booleans. It adds no extra features to IError. More...
class	Mcro::Error::FUnavailable
	A simple error type denoting that whatever is being accessed is not available like attempting to access nullptr. It adds no extra features to IError. More...
struct	Mcro::Error::TMaybe< T >
	A TValueOrError alternative for IError which allows implicit conversion from values and errors (no need for MakeError or MakeValue) and is boolean testable. It also doesn't have ambiguous state such as TValueOrError has, so a TMaybe will always have either an error or a value, it will never have neither of them or both of them. More...

Namespaces
namespace	Mcro
namespace	Mcro::Error
	Contains utilities for structured error handling.

Macros
#define	ERROR_LOG(categoryName, verbosity, error)
#define	ERROR_CLOG(condition, categoryName, verbosity, error)
#define	ASSERT_RETURN(condition)
	Similar to check() macro, but return an error instead of crashing.
#define	UNAVAILABLE()
	Denote that a resource which is asked for doesn't exist.
#define	MCRO_PROPAGATE_FAIL_3(type, var, expression)
#define	MCRO_PROPAGATE_FAIL_2(var, expression)
#define	MCRO_PROPAGATE_FAIL_1(expression)
#define	PROPAGATE_FAIL(...)
	If a function returns a TMaybe or an FCanFail inside another function which may also return another error use this convenience macro to propagate the failure.

Typedefs
using	Mcro::Error::FCanFail = TMaybe<FVoid>
	Indicate that an otherwise void function that it may fail with an IError.
using	Mcro::Error::FTrueOrReason = TMaybe<FVoid>
	Syntactically same as FCanFail but for functions which is explicitly used to query some boolean decidable thing, and which can also provide a reason why the queried thing is false.

Functions
FORCEINLINE FCanFail	Mcro::Error::Success ()
	Return an FCanFail or FTrueOrReason indicating a success or truthy output.

Detailed Description

Copyright

This Source Code is subject to the terms of the Mozilla Public License, v2.0. If a copy of the MPL was not distributed with this file You can obtain one at https://mozilla.org/MPL/2.0/

Author

David Mórász

Date

2025

Definition in file Error.h.

Macro Definition Documentation

ASSERT_RETURN

#define ASSERT_RETURN

(

condition

)

Value:

    if (UNLIKELY(!(condition)))                                         \
        return Mcro::Error::IError::Make(new Mcro::Error::FAssertion()) \
            ->WithLocation()                                            \
            ->AsRecoverable()                                           \
            ->WithCodeContext(PREPROCESSOR_TO_TEXT(condition))

Similar to check() macro, but return an error instead of crashing.

Definition at line 660 of file Error.h.

ERROR_CLOG

#define ERROR_CLOG	(		condition,
			categoryName,
			verbosity,
			error )

Value:

    UE_CLOG(condition, categoryName, verbosity, TEXT_"%s", *((error) \
        ->WithLocation()                                             \
        ->Report()                                                   \
        ->ToString()                                                 \
    ))

Definition at line 652 of file Error.h.

ERROR_LOG

#define ERROR_LOG	(		categoryName,
			verbosity,
			error )

Value:

    UE_LOG(categoryName, verbosity, TEXT_"%s", *((error) \
        ->WithLocation()                                 \
        ->Report()                                       \
        ->ToString()                                     \
    ))

Definition at line 645 of file Error.h.

MCRO_PROPAGATE_FAIL_1

#define MCRO_PROPAGATE_FAIL_1

(

expression

)

Value:

MCRO_PROPAGATE_FAIL_2(PREPROCESSOR_JOIN(tempResult, __LINE__), expression)

Definition at line 679 of file Error.h.

MCRO_PROPAGATE_FAIL_2

#define MCRO_PROPAGATE_FAIL_2	(		var,
			expression )

Value:

MCRO_PROPAGATE_FAIL_3(auto, var, expression)

Definition at line 678 of file Error.h.

MCRO_PROPAGATE_FAIL_3

#define MCRO_PROPAGATE_FAIL_3	(		type,
			var,
			expression )

Value:

    type var = (expression);                            \
    if (UNLIKELY(var.HasError())) return var.GetError() \
        ->WithLocation()

Definition at line 673 of file Error.h.

PROPAGATE_FAIL

#define PROPAGATE_FAIL

(

...

)

Value:

MACRO_OVERLOAD(MCRO_PROPAGATE_FAIL_, __VA_ARGS__)

If a function returns a TMaybe or an FCanFail inside another function which may also return another error use this convenience macro to propagate the failure.

The following overloads are available:

• (expression) Use this when the value of success is not needed further below. This will create a local variable with an automatically determined name and type
• (var, expression) Use this when the value of success will be used further below. The local variable will be created with auto
• (type, var, expression) Use this when the value of success will be used further below and its local variable should have an explicit type

Definition at line 694 of file Error.h.

UNAVAILABLE

#define UNAVAILABLE

(

)

Value:

    return Mcro::Error::IError::Make(new Mcro::Error::FUnavailable()) \
        ->WithLocation()                                              \
        ->AsRecoverable()

Denote that a resource which is asked for doesn't exist.

Definition at line 668 of file Error.h.