| /* |
| ******************************************************************************* |
| * |
| * Copyright (C) 2009-2010, International Business Machines |
| * Corporation and others. All Rights Reserved. |
| * |
| ******************************************************************************* |
| * file name: errorcode.h |
| * encoding: US-ASCII |
| * tab size: 8 (not used) |
| * indentation:4 |
| * |
| * created on: 2009mar10 |
| * created by: Markus W. Scherer |
| */ |
| |
| #ifndef __ERRORCODE_H__ |
| #define __ERRORCODE_H__ |
| |
| /** |
| * \file |
| * \brief C++ API: ErrorCode class intended to make it easier to use |
| * ICU C and C++ APIs from C++ user code. |
| */ |
| |
| #include "unicode/utypes.h" |
| #include "unicode/uobject.h" |
| |
| U_NAMESPACE_BEGIN |
| |
| /** |
| * Wrapper class for UErrorCode, with conversion operators for direct use |
| * in ICU C and C++ APIs. |
| * Intended to be used as a base class, where a subclass overrides |
| * the handleFailure() function so that it throws an exception, |
| * does an assert(), logs an error, etc. |
| * This is not an abstract base class. This class can be used and instantiated |
| * by itself, although it will be more useful when subclassed. |
| * |
| * Features: |
| * - The constructor initializes the internal UErrorCode to U_ZERO_ERROR, |
| * removing one common source of errors. |
| * - Same use in C APIs taking a UErrorCode * (pointer) |
| * and C++ taking UErrorCode & (reference) via conversion operators. |
| * - Possible automatic checking for success when it goes out of scope. |
| * |
| * Note: For automatic checking for success in the destructor, a subclass |
| * must implement such logic in its own destructor because the base class |
| * destructor cannot call a subclass function (like handleFailure()). |
| * The ErrorCode base class destructor does nothing. |
| * |
| * Note also: While it is possible for a destructor to throw an exception, |
| * it is generally unsafe to do so. This means that in a subclass the destructor |
| * and the handleFailure() function may need to take different actions. |
| * |
| * Sample code: |
| * \code |
| * class IcuErrorCode: public icu::ErrorCode { |
| * public: |
| * virtual ~IcuErrorCode() { |
| * // Safe because our handleFailure() does not throw exceptions. |
| * if(isFailure()) { handleFailure(); } |
| * } |
| * protected: |
| * virtual void handleFailure() const { |
| * log_failure(u_errorName(errorCode)); |
| * exit(errorCode); |
| * } |
| * }; |
| * IcuErrorCode error_code; |
| * UConverter *cnv = ucnv_open("Shift-JIS", error_code); |
| * length = ucnv_fromUChars(dest, capacity, src, length, error_code); |
| * ucnv_close(cnv); |
| * // IcuErrorCode destructor checks for success. |
| * \endcode |
| * |
| * @stable ICU 4.2 |
| */ |
| class U_COMMON_API ErrorCode: public UMemory { |
| public: |
| /** |
| * Default constructor. Initializes its UErrorCode to U_ZERO_ERROR. |
| * @stable ICU 4.2 |
| */ |
| ErrorCode() : errorCode(U_ZERO_ERROR) {} |
| /** Destructor, does nothing. See class documentation for details. @stable ICU 4.2 */ |
| virtual ~ErrorCode() {} |
| /** Conversion operator, returns a reference. @stable ICU 4.2 */ |
| operator UErrorCode & () { return errorCode; } |
| /** Conversion operator, returns a pointer. @stable ICU 4.2 */ |
| operator UErrorCode * () { return &errorCode; } |
| /** Tests for U_SUCCESS(). @stable ICU 4.2 */ |
| UBool isSuccess() const { return U_SUCCESS(errorCode); } |
| /** Tests for U_FAILURE(). @stable ICU 4.2 */ |
| UBool isFailure() const { return U_FAILURE(errorCode); } |
| /** Returns the UErrorCode value. @stable ICU 4.2 */ |
| UErrorCode get() const { return errorCode; } |
| /** Sets the UErrorCode value. @stable ICU 4.2 */ |
| void set(UErrorCode value) { errorCode=value; } |
| /** Returns the UErrorCode value and resets it to U_ZERO_ERROR. @stable ICU 4.2 */ |
| UErrorCode reset(); |
| /** |
| * Asserts isSuccess(). |
| * In other words, this method checks for a failure code, |
| * and the base class handles it like this: |
| * \code |
| * if(isFailure()) { handleFailure(); } |
| * \endcode |
| * @draft ICU 4.4 |
| */ |
| void assertSuccess() const; |
| /** |
| * Return a string for the UErrorCode value. |
| * The string will be the same as the name of the error code constant |
| * in the UErrorCode enum. |
| * @draft ICU 4.4 |
| */ |
| const char* errorName() const; |
| |
| protected: |
| /** |
| * Internal UErrorCode, accessible to subclasses. |
| * @stable ICU 4.2 |
| */ |
| UErrorCode errorCode; |
| /** |
| * Called by assertSuccess() if isFailure() is true. |
| * A subclass should override this function to deal with a failure code: |
| * Throw an exception, log an error, terminate the program, or similar. |
| * @stable ICU 4.2 |
| */ |
| virtual void handleFailure() const {} |
| }; |
| |
| U_NAMESPACE_END |
| |
| #endif // __ERRORCODE_H__ |