gecko/xpcom/string/public/nsXPCOMStrings.h
Mike Hommey ffa61edd96 Bug 852950 - Kill libxpcom. r=bsmedberg
Also refactored the xpcom standalone glue to reside in a single file and
removed its use of realpath().

--HG--
rename : xpcom/stub/dependentlibs.py => toolkit/library/dependentlibs.py
rename : xpcom/stub/nsXPComStub.cpp => xpcom/build/FrozenFunctions.cpp
2013-03-20 14:56:41 +01:00

764 lines
28 KiB
C++

/* vim:set ts=2 sw=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef nsXPCOMStrings_h__
#define nsXPCOMStrings_h__
#include <string.h>
#include "nscore.h"
#include <limits>
/**
* nsXPCOMStrings.h
*
* This file describes a minimal API for working with XPCOM's abstract
* string classes. It divorces the consumer from having any run-time
* dependency on the implementation details of the abstract string types.
*/
#include "nscore.h"
/* The base string types */
class nsAString;
class nsACString;
/* ------------------------------------------------------------------------- */
/**
* nsStringContainer
*
* This is an opaque data type that is large enough to hold the canonical
* implementation of nsAString. The binary structure of this class is an
* implementation detail.
*
* The string data stored in a string container is always single fragment
* and may be null-terminated depending on how it is initialized.
*
* Typically, string containers are allocated on the stack for temporary
* use. However, they can also be malloc'd if necessary. In either case,
* a string container is not useful until it has been initialized with a
* call to NS_StringContainerInit. The following example shows how to use
* a string container to call a function that takes a |nsAString &| out-param.
*
* NS_METHOD GetBlah(nsAString &aBlah);
*
* nsresult MyCode()
* {
* nsresult rv;
*
* nsStringContainer sc;
* rv = NS_StringContainerInit(sc);
* if (NS_FAILED(rv))
* return rv;
*
* rv = GetBlah(sc);
* if (NS_SUCCEEDED(rv))
* {
* const PRUnichar *data;
* NS_StringGetData(sc, &data);
* //
* // |data| now points to the result of the GetBlah function
* //
* }
*
* NS_StringContainerFinish(sc);
* return rv;
* }
*
* The following example show how to use a string container to pass a string
* parameter to a function taking a |const nsAString &| in-param.
*
* NS_METHOD SetBlah(const nsAString &aBlah);
*
* nsresult MyCode()
* {
* nsresult rv;
*
* nsStringContainer sc;
* rv = NS_StringContainerInit(sc);
* if (NS_FAILED(rv))
* return rv;
*
* const PRUnichar kData[] = {'x','y','z','\0'};
* rv = NS_StringSetData(sc, kData, sizeof(kData)/2 - 1);
* if (NS_SUCCEEDED(rv))
* rv = SetBlah(sc);
*
* NS_StringContainerFinish(sc);
* return rv;
* }
*/
class nsStringContainer;
/**
* This struct is never used directly. It is designed to have the same
* size as nsString. It can be stack and heap allocated and the internal
* functions cast it to nsString.
* While this practice is a strict aliasing violation, it doesn't seem to
* cause problems since the the struct is only accessed via the casts to
* nsString.
* We use protected instead of private to avoid compiler warnings about
* the members being unused.
*/
struct nsStringContainer_base
{
protected:
void *d1;
uint32_t d2;
uint32_t d3;
};
/**
* Flags that may be OR'd together to pass to NS_StringContainerInit2:
*/
enum {
/* Data passed into NS_StringContainerInit2 is not copied; instead, the
* string references the passed in data pointer directly. The caller must
* ensure that the data is valid for the lifetime of the string container.
* This flag should not be combined with NS_STRING_CONTAINER_INIT_ADOPT. */
NS_STRING_CONTAINER_INIT_DEPEND = (1 << 1),
/* Data passed into NS_StringContainerInit2 is not copied; instead, the
* string takes ownership over the data pointer. The caller must have
* allocated the data array using the XPCOM memory allocator (nsMemory).
* This flag should not be combined with NS_STRING_CONTAINER_INIT_DEPEND. */
NS_STRING_CONTAINER_INIT_ADOPT = (1 << 2),
/* Data passed into NS_StringContainerInit2 is a substring that is not
* null-terminated. */
NS_STRING_CONTAINER_INIT_SUBSTRING = (1 << 3)
};
/**
* NS_StringContainerInit
*
* @param aContainer string container reference
* @return NS_OK if string container successfully initialized
*
* This function may allocate additional memory for aContainer. When
* aContainer is no longer needed, NS_StringContainerFinish should be called.
*/
XPCOM_API(nsresult)
NS_StringContainerInit(nsStringContainer &aContainer);
/**
* NS_StringContainerInit2
*
* @param aContainer string container reference
* @param aData character buffer (may be null)
* @param aDataLength number of characters stored at aData (may pass
* UINT32_MAX if aData is null-terminated)
* @param aFlags flags affecting how the string container is
* initialized. this parameter is ignored when aData
* is null. otherwise, if this parameter is 0, then
* aData is copied into the string.
*
* This function resembles NS_StringContainerInit but provides further
* options that permit more efficient memory usage. When aContainer is
* no longer needed, NS_StringContainerFinish should be called.
*
* NOTE: NS_StringContainerInit2(container, nullptr, 0, 0) is equivalent to
* NS_StringContainerInit(container).
*/
XPCOM_API(nsresult)
NS_StringContainerInit2
(nsStringContainer &aContainer, const PRUnichar *aData = nullptr,
uint32_t aDataLength = UINT32_MAX, uint32_t aFlags = 0);
/**
* NS_StringContainerFinish
*
* @param aContainer string container reference
*
* This function frees any memory owned by aContainer.
*/
XPCOM_API(void)
NS_StringContainerFinish(nsStringContainer &aContainer);
/* ------------------------------------------------------------------------- */
/**
* NS_StringGetData
*
* This function returns a const character pointer to the string's internal
* buffer, the length of the string, and a boolean value indicating whether
* or not the buffer is null-terminated.
*
* @param aStr abstract string reference
* @param aData out param that will hold the address of aStr's
* internal buffer
* @param aTerminated if non-null, this out param will be set to indicate
* whether or not aStr's internal buffer is null-
* terminated
* @return length of aStr's internal buffer
*/
XPCOM_API(uint32_t)
NS_StringGetData
(const nsAString &aStr, const PRUnichar **aData,
bool *aTerminated = nullptr);
/**
* NS_StringGetMutableData
*
* This function provides mutable access to a string's internal buffer. It
* returns a pointer to an array of characters that may be modified. The
* returned pointer remains valid until the string object is passed to some
* other string function.
*
* Optionally, this function may be used to resize the string's internal
* buffer. The aDataLength parameter specifies the requested length of the
* string's internal buffer. By passing some value other than UINT32_MAX,
* the caller can request that the buffer be resized to the specified number of
* characters before returning. The caller is not responsible for writing a
* null-terminator.
*
* @param aStr abstract string reference
* @param aDataLength number of characters to resize the string's internal
* buffer to or UINT32_MAX if no resizing is needed
* @param aData out param that upon return holds the address of aStr's
* internal buffer or null if the function failed
* @return number of characters or zero if the function failed
*
* This function does not necessarily null-terminate aStr after resizing its
* internal buffer. The behavior depends on the implementation of the abstract
* string, aStr. If aStr is a reference to a nsStringContainer, then its data
* will be null-terminated by this function.
*/
XPCOM_API(uint32_t)
NS_StringGetMutableData
(nsAString &aStr, uint32_t aDataLength, PRUnichar **aData);
/**
* NS_StringCloneData
*
* This function returns a null-terminated copy of the string's
* internal buffer.
*
* @param aStr abstract string reference
* @return null-terminated copy of the string's internal buffer
* (it must be free'd using using nsMemory::Free)
*/
XPCOM_API(PRUnichar *)
NS_StringCloneData
(const nsAString &aStr);
/**
* NS_StringSetData
*
* This function copies aData into aStr.
*
* @param aStr abstract string reference
* @param aData character buffer
* @param aDataLength number of characters to copy from source string (pass
* UINT32_MAX to copy until end of aData, designated by
* a null character)
* @return NS_OK if function succeeded
*
* This function does not necessarily null-terminate aStr after copying data
* from aData. The behavior depends on the implementation of the abstract
* string, aStr. If aStr is a reference to a nsStringContainer, then its data
* will be null-terminated by this function.
*/
XPCOM_API(nsresult)
NS_StringSetData
(nsAString &aStr, const PRUnichar *aData,
uint32_t aDataLength = UINT32_MAX);
/**
* NS_StringSetDataRange
*
* This function copies aData into a section of aStr. As a result it can be
* used to insert new characters into the string.
*
* @param aStr abstract string reference
* @param aCutOffset starting index where the string's existing data
* is to be overwritten (pass UINT32_MAX to cause
* aData to be appended to the end of aStr, in which
* case the value of aCutLength is ignored).
* @param aCutLength number of characters to overwrite starting at
* aCutOffset (pass UINT32_MAX to overwrite until the
* end of aStr).
* @param aData character buffer (pass null to cause this function
* to simply remove the "cut" range)
* @param aDataLength number of characters to copy from source string (pass
* UINT32_MAX to copy until end of aData, designated by
* a null character)
* @return NS_OK if function succeeded
*
* This function does not necessarily null-terminate aStr after copying data
* from aData. The behavior depends on the implementation of the abstract
* string, aStr. If aStr is a reference to a nsStringContainer, then its data
* will be null-terminated by this function.
*/
XPCOM_API(nsresult)
NS_StringSetDataRange
(nsAString &aStr, uint32_t aCutOffset, uint32_t aCutLength,
const PRUnichar *aData, uint32_t aDataLength = UINT32_MAX);
/**
* NS_StringCopy
*
* This function makes aDestStr have the same value as aSrcStr. It is
* provided as an optimization.
*
* @param aDestStr abstract string reference to be modified
* @param aSrcStr abstract string reference containing source string
* @return NS_OK if function succeeded
*
* This function does not necessarily null-terminate aDestStr after copying
* data from aSrcStr. The behavior depends on the implementation of the
* abstract string, aDestStr. If aDestStr is a reference to a
* nsStringContainer, then its data will be null-terminated by this function.
*/
XPCOM_API(nsresult)
NS_StringCopy
(nsAString &aDestStr, const nsAString &aSrcStr);
/**
* NS_StringAppendData
*
* This function appends data to the existing value of aStr.
*
* @param aStr abstract string reference to be modified
* @param aData character buffer
* @param aDataLength number of characters to append (pass UINT32_MAX to
* append until a null-character is encountered)
* @return NS_OK if function succeeded
*
* This function does not necessarily null-terminate aStr upon completion.
* The behavior depends on the implementation of the abstract string, aStr.
* If aStr is a reference to a nsStringContainer, then its data will be null-
* terminated by this function.
*/
inline NS_HIDDEN_(nsresult)
NS_StringAppendData(nsAString &aStr, const PRUnichar *aData,
uint32_t aDataLength = UINT32_MAX)
{
return NS_StringSetDataRange(aStr, UINT32_MAX, 0, aData, aDataLength);
}
/**
* NS_StringInsertData
*
* This function inserts data into the existing value of aStr at the specified
* offset.
*
* @param aStr abstract string reference to be modified
* @param aOffset specifies where in the string to insert aData
* @param aData character buffer
* @param aDataLength number of characters to append (pass UINT32_MAX to
* append until a null-character is encountered)
* @return NS_OK if function succeeded
*
* This function does not necessarily null-terminate aStr upon completion.
* The behavior depends on the implementation of the abstract string, aStr.
* If aStr is a reference to a nsStringContainer, then its data will be null-
* terminated by this function.
*/
inline NS_HIDDEN_(nsresult)
NS_StringInsertData(nsAString &aStr, uint32_t aOffset, const PRUnichar *aData,
uint32_t aDataLength = UINT32_MAX)
{
return NS_StringSetDataRange(aStr, aOffset, 0, aData, aDataLength);
}
/**
* NS_StringCutData
*
* This function shortens the existing value of aStr, by removing characters
* at the specified offset.
*
* @param aStr abstract string reference to be modified
* @param aCutOffset specifies where in the string to insert aData
* @param aCutLength number of characters to remove
* @return NS_OK if function succeeded
*/
inline NS_HIDDEN_(nsresult)
NS_StringCutData(nsAString &aStr, uint32_t aCutOffset, uint32_t aCutLength)
{
return NS_StringSetDataRange(aStr, aCutOffset, aCutLength, nullptr, 0);
}
/**
* NS_StringSetIsVoid
*
* This function marks a string as being a "void string". Any data in the
* string will be lost.
*/
XPCOM_API(void)
NS_StringSetIsVoid(nsAString& aStr, const bool aIsVoid);
/**
* NS_StringGetIsVoid
*
* This function provides a way to test if a string is a "void string", as
* marked by NS_StringSetIsVoid.
*/
XPCOM_API(bool)
NS_StringGetIsVoid(const nsAString& aStr);
/* ------------------------------------------------------------------------- */
/**
* nsCStringContainer
*
* This is an opaque data type that is large enough to hold the canonical
* implementation of nsACString. The binary structure of this class is an
* implementation detail.
*
* The string data stored in a string container is always single fragment
* and may be null-terminated depending on how it is initialized.
*
* @see nsStringContainer for use cases and further documentation.
*/
class nsCStringContainer;
/**
* Flags that may be OR'd together to pass to NS_StringContainerInit2:
*/
enum {
/* Data passed into NS_CStringContainerInit2 is not copied; instead, the
* string references the passed in data pointer directly. The caller must
* ensure that the data is valid for the lifetime of the string container.
* This flag should not be combined with NS_CSTRING_CONTAINER_INIT_ADOPT. */
NS_CSTRING_CONTAINER_INIT_DEPEND = (1 << 1),
/* Data passed into NS_CStringContainerInit2 is not copied; instead, the
* string takes ownership over the data pointer. The caller must have
* allocated the data array using the XPCOM memory allocator (nsMemory).
* This flag should not be combined with NS_CSTRING_CONTAINER_INIT_DEPEND. */
NS_CSTRING_CONTAINER_INIT_ADOPT = (1 << 2),
/* Data passed into NS_CStringContainerInit2 is a substring that is not
* null-terminated. */
NS_CSTRING_CONTAINER_INIT_SUBSTRING = (1 << 3)
};
/**
* NS_CStringContainerInit
*
* @param aContainer string container reference
* @return NS_OK if string container successfully initialized
*
* This function may allocate additional memory for aContainer. When
* aContainer is no longer needed, NS_CStringContainerFinish should be called.
*/
XPCOM_API(nsresult)
NS_CStringContainerInit(nsCStringContainer &aContainer);
/**
* NS_CStringContainerInit2
*
* @param aContainer string container reference
* @param aData character buffer (may be null)
* @param aDataLength number of characters stored at aData (may pass
* UINT32_MAX if aData is null-terminated)
* @param aFlags flags affecting how the string container is
* initialized. this parameter is ignored when aData
* is null. otherwise, if this parameter is 0, then
* aData is copied into the string.
*
* This function resembles NS_CStringContainerInit but provides further
* options that permit more efficient memory usage. When aContainer is
* no longer needed, NS_CStringContainerFinish should be called.
*
* NOTE: NS_CStringContainerInit2(container, nullptr, 0, 0) is equivalent to
* NS_CStringContainerInit(container).
*/
XPCOM_API(nsresult)
NS_CStringContainerInit2
(nsCStringContainer &aContainer, const char *aData = nullptr,
uint32_t aDataLength = UINT32_MAX, uint32_t aFlags = 0);
/**
* NS_CStringContainerFinish
*
* @param aContainer string container reference
*
* This function frees any memory owned by aContainer.
*/
XPCOM_API(void)
NS_CStringContainerFinish(nsCStringContainer &aContainer);
/* ------------------------------------------------------------------------- */
/**
* NS_CStringGetData
*
* This function returns a const character pointer to the string's internal
* buffer, the length of the string, and a boolean value indicating whether
* or not the buffer is null-terminated.
*
* @param aStr abstract string reference
* @param aData out param that will hold the address of aStr's
* internal buffer
* @param aTerminated if non-null, this out param will be set to indicate
* whether or not aStr's internal buffer is null-
* terminated
* @return length of aStr's internal buffer
*/
XPCOM_API(uint32_t)
NS_CStringGetData
(const nsACString &aStr, const char **aData,
bool *aTerminated = nullptr);
/**
* NS_CStringGetMutableData
*
* This function provides mutable access to a string's internal buffer. It
* returns a pointer to an array of characters that may be modified. The
* returned pointer remains valid until the string object is passed to some
* other string function.
*
* Optionally, this function may be used to resize the string's internal
* buffer. The aDataLength parameter specifies the requested length of the
* string's internal buffer. By passing some value other than UINT32_MAX,
* the caller can request that the buffer be resized to the specified number of
* characters before returning. The caller is not responsible for writing a
* null-terminator.
*
* @param aStr abstract string reference
* @param aDataLength number of characters to resize the string's internal
* buffer to or UINT32_MAX if no resizing is needed
* @param aData out param that upon return holds the address of aStr's
* internal buffer or null if the function failed
* @return number of characters or zero if the function failed
*
* This function does not necessarily null-terminate aStr after resizing its
* internal buffer. The behavior depends on the implementation of the abstract
* string, aStr. If aStr is a reference to a nsStringContainer, then its data
* will be null-terminated by this function.
*/
XPCOM_API(uint32_t)
NS_CStringGetMutableData
(nsACString &aStr, uint32_t aDataLength, char **aData);
/**
* NS_CStringCloneData
*
* This function returns a null-terminated copy of the string's
* internal buffer.
*
* @param aStr abstract string reference
* @return null-terminated copy of the string's internal buffer
* (it must be free'd using using nsMemory::Free)
*/
XPCOM_API(char *)
NS_CStringCloneData
(const nsACString &aStr);
/**
* NS_CStringSetData
*
* This function copies aData into aStr.
*
* @param aStr abstract string reference
* @param aData character buffer
* @param aDataLength number of characters to copy from source string (pass
* UINT32_MAX to copy until end of aData, designated by
* a null character)
* @return NS_OK if function succeeded
*
* This function does not necessarily null-terminate aStr after copying data
* from aData. The behavior depends on the implementation of the abstract
* string, aStr. If aStr is a reference to a nsStringContainer, then its data
* will be null-terminated by this function.
*/
XPCOM_API(nsresult)
NS_CStringSetData
(nsACString &aStr, const char *aData,
uint32_t aDataLength = UINT32_MAX);
/**
* NS_CStringSetDataRange
*
* This function copies aData into a section of aStr. As a result it can be
* used to insert new characters into the string.
*
* @param aStr abstract string reference
* @param aCutOffset starting index where the string's existing data
* is to be overwritten (pass UINT32_MAX to cause
* aData to be appended to the end of aStr, in which
* case the value of aCutLength is ignored).
* @param aCutLength number of characters to overwrite starting at
* aCutOffset (pass UINT32_MAX to overwrite until the
* end of aStr).
* @param aData character buffer (pass null to cause this function
* to simply remove the "cut" range)
* @param aDataLength number of characters to copy from source string (pass
* UINT32_MAX to copy until end of aData, designated by
* a null character)
* @return NS_OK if function succeeded
*
* This function does not necessarily null-terminate aStr after copying data
* from aData. The behavior depends on the implementation of the abstract
* string, aStr. If aStr is a reference to a nsStringContainer, then its data
* will be null-terminated by this function.
*/
XPCOM_API(nsresult)
NS_CStringSetDataRange
(nsACString &aStr, uint32_t aCutOffset, uint32_t aCutLength,
const char *aData, uint32_t aDataLength = UINT32_MAX);
/**
* NS_CStringCopy
*
* This function makes aDestStr have the same value as aSrcStr. It is
* provided as an optimization.
*
* @param aDestStr abstract string reference to be modified
* @param aSrcStr abstract string reference containing source string
* @return NS_OK if function succeeded
*
* This function does not necessarily null-terminate aDestStr after copying
* data from aSrcStr. The behavior depends on the implementation of the
* abstract string, aDestStr. If aDestStr is a reference to a
* nsStringContainer, then its data will be null-terminated by this function.
*/
XPCOM_API(nsresult)
NS_CStringCopy
(nsACString &aDestStr, const nsACString &aSrcStr);
/**
* NS_CStringAppendData
*
* This function appends data to the existing value of aStr.
*
* @param aStr abstract string reference to be modified
* @param aData character buffer
* @param aDataLength number of characters to append (pass UINT32_MAX to
* append until a null-character is encountered)
* @return NS_OK if function succeeded
*
* This function does not necessarily null-terminate aStr upon completion.
* The behavior depends on the implementation of the abstract string, aStr.
* If aStr is a reference to a nsStringContainer, then its data will be null-
* terminated by this function.
*/
inline NS_HIDDEN_(nsresult)
NS_CStringAppendData(nsACString &aStr, const char *aData,
uint32_t aDataLength = UINT32_MAX)
{
return NS_CStringSetDataRange(aStr, UINT32_MAX, 0, aData, aDataLength);
}
/**
* NS_CStringInsertData
*
* This function inserts data into the existing value of aStr at the specified
* offset.
*
* @param aStr abstract string reference to be modified
* @param aOffset specifies where in the string to insert aData
* @param aData character buffer
* @param aDataLength number of characters to append (pass UINT32_MAX to
* append until a null-character is encountered)
* @return NS_OK if function succeeded
*
* This function does not necessarily null-terminate aStr upon completion.
* The behavior depends on the implementation of the abstract string, aStr.
* If aStr is a reference to a nsStringContainer, then its data will be null-
* terminated by this function.
*/
inline NS_HIDDEN_(nsresult)
NS_CStringInsertData(nsACString &aStr, uint32_t aOffset, const char *aData,
uint32_t aDataLength = UINT32_MAX)
{
return NS_CStringSetDataRange(aStr, aOffset, 0, aData, aDataLength);
}
/**
* NS_CStringCutData
*
* This function shortens the existing value of aStr, by removing characters
* at the specified offset.
*
* @param aStr abstract string reference to be modified
* @param aCutOffset specifies where in the string to insert aData
* @param aCutLength number of characters to remove
* @return NS_OK if function succeeded
*/
inline NS_HIDDEN_(nsresult)
NS_CStringCutData(nsACString &aStr, uint32_t aCutOffset, uint32_t aCutLength)
{
return NS_CStringSetDataRange(aStr, aCutOffset, aCutLength, nullptr, 0);
}
/**
* NS_CStringSetIsVoid
*
* This function marks a string as being a "void string". Any data in the
* string will be lost.
*/
XPCOM_API(void)
NS_CStringSetIsVoid(nsACString& aStr, const bool aIsVoid);
/**
* NS_CStringGetIsVoid
*
* This function provides a way to test if a string is a "void string", as
* marked by NS_CStringSetIsVoid.
*/
XPCOM_API(bool)
NS_CStringGetIsVoid(const nsACString& aStr);
/* ------------------------------------------------------------------------- */
/**
* Encodings that can be used with the following conversion routines.
*/
enum nsCStringEncoding {
/* Conversion between ASCII and UTF-16 assumes that all bytes in the source
* string are 7-bit ASCII and can be inflated to UTF-16 by inserting null
* bytes. Reverse conversion is done by truncating every other byte. The
* conversion may result in loss and/or corruption of information if the
* strings do not strictly contain ASCII data. */
NS_CSTRING_ENCODING_ASCII = 0,
/* Conversion between UTF-8 and UTF-16 is non-lossy. */
NS_CSTRING_ENCODING_UTF8 = 1,
/* Conversion from UTF-16 to the native filesystem charset may result in a
* loss of information. No attempt is made to protect against data loss in
* this case. The native filesystem charset applies to strings passed to
* the "Native" method variants on nsIFile. */
NS_CSTRING_ENCODING_NATIVE_FILESYSTEM = 2
};
/**
* NS_CStringToUTF16
*
* This function converts the characters in a nsACString to an array of UTF-16
* characters, in the platform endianness. The result is stored in a nsAString
* object.
*
* @param aSource abstract string reference containing source string
* @param aSrcEncoding character encoding of the source string
* @param aDest abstract string reference to hold the result
*/
XPCOM_API(nsresult)
NS_CStringToUTF16(const nsACString &aSource, nsCStringEncoding aSrcEncoding,
nsAString &aDest);
/**
* NS_UTF16ToCString
*
* This function converts the UTF-16 characters in a nsAString to a single-byte
* encoding. The result is stored in a nsACString object. In some cases this
* conversion may be lossy. In such cases, the conversion may succeed with a
* return code indicating loss of information. The exact behavior is not
* specified at this time.
*
* @param aSource abstract string reference containing source string
* @param aDestEncoding character encoding of the resulting string
* @param aDest abstract string reference to hold the result
*/
XPCOM_API(nsresult)
NS_UTF16ToCString(const nsAString &aSource, nsCStringEncoding aDestEncoding,
nsACString &aDest);
#endif // nsXPCOMStrings_h__