X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/c2b527b3ea8007dff526018f2f60dba8ff99b294..HEAD:/sv.h

diff --git a/sv.h b/sv.h
index d8ace32..240986c 100644
--- a/sv.h
+++ b/sv.h
@@ -320,12 +320,11 @@ C<SvREFCNT_inc_simple_void_NN> can only be used with expressions without side
 effects, you don't need the return value, and you know C<sv> is not C<NULL>.
 
 =for apidoc SvREFCNT_dec
-Decrements the reference count of the given SV.  C<sv> may be C<NULL>.
+=for apidoc_item SvREFCNT_dec_NN
 
-=for apidoc SvREFCNT_dec_NN
-Same as C<SvREFCNT_dec>, but can only be used if you know C<sv>
-is not C<NULL>.  Since we don't have to check the NULLness, it's faster
-and smaller.
+These decrement the reference count of the given SV.
+
+C<SvREFCNT_dec_NN> may only be used when C<sv> is known to not be C<NULL>.
 
 =for apidoc Am|svtype|SvTYPE|SV* sv
 Returns the type of the SV.  See C<L</svtype>>.
@@ -748,7 +747,7 @@ Returns a boolean indicating whether the SV contains a v-string.
 =for apidoc Am|U32|SvOOK|SV* sv
 Returns a U32 indicating whether the pointer to the string buffer is offset.
 This hack is used internally to speed up removal of characters from the
-beginning of a C<SvPV>.  When C<SvOOK> is true, then the start of the
+beginning of a C<L</SvPV>>.  When C<SvOOK> is true, then the start of the
 allocated string buffer is actually C<SvOOK_offset()> bytes before C<SvPVX>.
 This offset used to be stored in C<SvIVX>, but is now stored within the spare
 part of the buffer.
@@ -802,7 +801,9 @@ compiler will complain if you were to try to modify the contents of the string,
 (unless you cast away const yourself).
 
 =for apidoc Am|STRLEN|SvCUR|SV* sv
-Returns the length of the string which is in the SV.  See C<L</SvLEN>>.
+Returns the length, in bytes, of the PV inside the SV.
+Note that this may not match Perl's C<length>; for that, use
+C<sv_len_utf8(sv)>. See C<L</SvLEN>> also.
 
 =for apidoc Am|STRLEN|SvLEN|SV* sv
 Returns the size of the string buffer in the SV, not including any part
@@ -856,8 +857,8 @@ Set the value of the MAGIC pointer in C<sv> to val.  See C<L</SvIV_set>>.
 Set the value of the STASH pointer in C<sv> to val.  See C<L</SvIV_set>>.
 
 =for apidoc Am|void|SvCUR_set|SV* sv|STRLEN len
-Set the current length of the string which is in the SV.  See C<L</SvCUR>>
-and C<SvIV_set>>.
+Sets the current length, in bytes, of the C string which is in the SV.
+See C<L</SvCUR>> and C<SvIV_set>>.
 
 =for apidoc Am|void|SvLEN_set|SV* sv|STRLEN len
 Set the size of the string buffer for the SV. See C<L</SvLEN>>.
@@ -923,7 +924,7 @@ Set the size of the string buffer for the SV. See C<L</SvLEN>>.
 =for apidoc Am|U32|SvUTF8|SV* sv
 Returns a U32 value indicating the UTF-8 status of an SV.  If things are set-up
 properly, this indicates whether or not the SV contains UTF-8 encoded data.
-You should use this I<after> a call to C<SvPV()> or one of its variants, in
+You should use this I<after> a call to C<L</SvPV>> or one of its variants, in
 case any call to string overloading updates the internal flag.
 
 If you want to take into account the L<bytes> pragma, use C<L</DO_UTF8>>
@@ -1384,6 +1385,17 @@ object type. Exposed to perl code via Internals::SvREADONLY().
 	STMT_START { assert(SvTYPE(sv) >= SVt_PV); \
 		SvCUR_set(sv, (val) - SvPVX(sv)); } STMT_END
 
+/*
+=for apidoc Am|void|SvPV_renew|SV* sv|STRLEN len
+Low level micro optimization of C<L</SvGROW>>.  It is generally better to use
+C<SvGROW> instead.  This is because C<SvPV_renew> ignores potential issues that
+C<SvGROW> handles.  C<sv> needs to have a real C<PV> that is unencombered by
+things like COW.  Using C<SV_CHECK_THINKFIRST> or
+C<SV_CHECK_THINKFIRST_COW_DROP> before calling this should clean it up, but
+why not just use C<SvGROW> if you're not sure about the provenance?
+
+=cut
+*/
 #define SvPV_renew(sv,n) \
 	STMT_START { SvLEN_set(sv, n); \
 		SvPV_set((sv), (MEM_WRAP_CHECK_(n,char)			\
@@ -1543,9 +1555,23 @@ attention to precisely which outputs are influenced by which inputs.
 
 /*
 =for apidoc Am|char*|SvPV_force|SV* sv|STRLEN len
-Like C<SvPV> but will force the SV into containing a string (C<SvPOK>), and
-only a string (C<SvPOK_only>), by hook or by crook.  You need force if you are
-going to update the C<SvPVX> directly.  Processes get magic.
+=for apidoc_item ||SvPV_force_nolen|SV* sv
+=for apidoc_item ||SvPVx_force|SV* sv|STRLEN len
+=for apidoc_item ||SvPV_force_nomg|SV* sv|STRLEN len
+=for apidoc_item ||SvPV_force_nomg_nolen|SV * sv
+=for apidoc_item ||SvPV_force_mutable|SV * sv|STRLEN len
+=for apidoc_item ||SvPV_force_flags|SV * sv|STRLEN len|U32 flags
+=for apidoc_item ||SvPV_force_flags_nolen|SV * sv|U32 flags
+=for apidoc_item ||SvPV_force_flags_mutable|SV * sv|STRLEN len|U32 flags
+=for apidoc_item ||SvPVbyte_force
+=for apidoc_item ||SvPVbytex_force
+=for apidoc_item ||SvPVutf8_force
+=for apidoc_item ||SvPVutf8x_force
+
+These are like C<L</SvPV>>, returning the string in the SV, but will force the
+SV into containing a string (C<L</SvPOK>>), and only a string
+(C<L</SvPOK_only>>), by hook or by crook.  You need to use one of these
+C<force> routines if you are going to update the C<L</SvPVX>> directly.
 
 Note that coercing an arbitrary scalar into a plain PV will potentially
 strip useful data from it.  For example if the SV was C<SvROK>, then the
@@ -1553,39 +1579,134 @@ referent will have its reference count decremented, and the SV itself may
 be converted to an C<SvPOK> scalar with a string buffer containing a value
 such as C<"ARRAY(0x1234)">.
 
-=for apidoc Am|char*|SvPV_force_nomg|SV* sv|STRLEN len
-Like C<SvPV_force>, but doesn't process get magic.
+The differences between the forms are:
+
+The forms with C<flags> in their names allow you to use the C<flags> parameter
+to specify to perform 'get' magic (by setting the C<SV_GMAGIC> flag) or to skip
+'get' magic (by clearing it).  The other forms do perform 'get' magic, except
+for the ones with C<nomg> in their names, which skip 'get' magic.
+
+The forms that take a C<len> parameter will set that variable to the byte
+length of the resultant string (these are macros, so don't use C<&len>).
+
+The forms with C<nolen> in their names indicate they don't have a C<len>
+parameter.  They should be used only when it is known that the PV is a C
+string, terminated by a NUL byte, and without intermediate NUL characters; or
+when you don't care about its length.
+
+The forms with C<mutable> in their names are effectively the same as those without,
+but the name emphasizes that the string is modifiable by the caller, which it is
+in all the forms.
+
+C<SvPVutf8_force> is like C<SvPV_force>, but converts C<sv> to UTF-8 first if
+not already UTF-8.
+
+C<SvPVutf8x_force> is like C<SvPVutf8_force>, but guarantees to evaluate C<sv>
+only once; use the more efficient C<SvPVutf8_force> otherwise.
+
+C<SvPVbyte_force> is like C<SvPV_force>, but converts C<sv> to byte
+representation first if currently encoded as UTF-8.  If the SV cannot be
+downgraded from UTF-8, this croaks.
+
+C<SvPVbytex_force> is like C<SvPVbyte_force>, but guarantees to evaluate C<sv>
+only once; use the more efficient C<SvPVbyte_force> otherwise.
 
 =for apidoc Am|char*|SvPV|SV* sv|STRLEN len
-Returns a pointer to the string in the SV, or a stringified form of
-the SV if the SV does not contain a string.  The SV may cache the
-stringified version becoming C<SvPOK>.  Handles 'get' magic.  The
-C<len> variable will be set to the length of the string (this is a macro, so
-don't use C<&len>).  See also C<L</SvPVx>> for a version which guarantees to
-evaluate C<sv> only once.
-
-Note that there is no guarantee that the return value of C<SvPV()> is
-equal to C<SvPVX(sv)>, or that C<SvPVX(sv)> contains valid data, or that
-successive calls to C<SvPV(sv)> will return the same pointer value each
-time.  This is due to the way that things like overloading and
-Copy-On-Write are handled.  In these cases, the return value may point to
-a temporary buffer or similar.  If you absolutely need the C<SvPVX> field to
-be valid (for example, if you intend to write to it), then see
-C<L</SvPV_force>>.
-
-=for apidoc Am|char*|SvPVx|SV* sv|STRLEN len
-A version of C<SvPV> which guarantees to evaluate C<sv> only once.
-Only use this if C<sv> is an expression with side effects, otherwise use the
-more efficient C<SvPV>.
-
-=for apidoc Am|char*|SvPV_nomg|SV* sv|STRLEN len
-Like C<SvPV> but doesn't process magic.
-
-=for apidoc Am|char*|SvPV_nolen|SV* sv
-Like C<SvPV> but doesn't set a length variable.
-
-=for apidoc Am|char*|SvPV_nomg_nolen|SV* sv
-Like C<SvPV_nolen> but doesn't process magic.
+=for apidoc_item |char*|SvPVx|SV* sv|STRLEN len
+=for apidoc_item |char*|SvPV_nomg|SV* sv|STRLEN len
+=for apidoc_item |char*|SvPV_nolen|SV* sv
+=for apidoc_item |char*|SvPVx_nolen|SV* sv
+=for apidoc_item |char*|SvPV_nomg_nolen|SV* sv
+=for apidoc_item |char*|SvPV_mutable|SV* sv|STRLEN len
+=for apidoc_item |const char*|SvPV_const|SV* sv|STRLEN len
+=for apidoc_item |const char*|SvPVx_const|SV* sv|STRLEN len
+=for apidoc_item |const char*|SvPV_nolen_const|SV* sv
+=for apidoc_item |const char*|SvPVx_nolen_const|SV* sv
+=for apidoc_item |const char*|SvPV_nomg_const|SV* sv|STRLEN len
+=for apidoc_item |const char*|SvPV_nomg_const_nolen|SV* sv
+=for apidoc_item |char *|SvPV_flags|SV * sv|STRLEN len|U32 flags
+=for apidoc_item |const char *|SvPV_flags_const|SV * sv|STRLEN len|U32 flags
+=for apidoc_item |char *|SvPV_flags_mutable|SV * sv|STRLEN len|U32 flags
+=for apidoc_item |char*|SvPVbyte|SV* sv|STRLEN len
+=for apidoc_item |char*|SvPVbyte_nomg|SV* sv|STRLEN len
+=for apidoc_item |char*|SvPVbyte_nolen|SV* sv
+=for apidoc_item |char*|SvPVbytex_nolen|SV* sv
+=for apidoc_item |char*|SvPVbytex|SV* sv|STRLEN len
+=for apidoc_item |char*|SvPVbyte_or_null|SV* sv|STRLEN len
+=for apidoc_item |char*|SvPVbyte_or_null_nomg|SV* sv|STRLEN len
+=for apidoc_item |char*|SvPVutf8|SV* sv|STRLEN len
+=for apidoc_item |char*|SvPVutf8x|SV* sv|STRLEN len
+=for apidoc_item |char*|SvPVutf8_nomg|SV* sv|STRLEN len
+=for apidoc_item |char*|SvPVutf8_nolen|SV* sv
+=for apidoc_item |char*|SvPVutf8_or_null|SV* sv|STRLEN len
+=for apidoc_item |char*|SvPVutf8_or_null_nomg|SV* sv|STRLEN len
+
+All these return a pointer to the string in C<sv>, or a stringified form of
+C<sv> if it does not contain a string.  The SV may cache the stringified
+version becoming C<SvPOK>.
+
+This is a very basic and common operation, so there are lots of slightly
+different versions of it.
+
+Note that there is no guarantee that the return value of C<SvPV(sv)>, for
+example, is equal to C<SvPVX(sv)>, or that C<SvPVX(sv)> contains valid data, or
+that successive calls to C<SvPV(sv)> (or another of these forms) will return
+the same pointer value each time.  This is due to the way that things like
+overloading and Copy-On-Write are handled.  In these cases, the return value
+may point to a temporary buffer or similar.  If you absolutely need the
+C<SvPVX> field to be valid (for example, if you intend to write to it), then
+see C<L</SvPV_force>>.
+
+The differences between the forms are:
+
+The forms with neither C<byte> nor C<utf8> in their names (e.g., C<SvPV> or
+C<SvPV_nolen>) can expose the SV's internal string buffer. If
+that buffer consists entirely of bytes 0-255 and includes any bytes above
+127, then you B<MUST> consult C<SvUTF8> to determine the actual code points
+the string is meant to contain. Generally speaking, it is probably safer to
+prefer C<SvPVbyte>, C<SvPVutf8>, and the like. See
+L<perlguts/How do I pass a Perl string to a C library?> for more details.
+
+The forms with C<flags> in their names allow you to use the C<flags> parameter
+to specify to process 'get' magic (by setting the C<SV_GMAGIC> flag) or to skip
+'get' magic (by clearing it).  The other forms process 'get' magic, except for
+the ones with C<nomg> in their names, which skip 'get' magic.
+
+The forms that take a C<len> parameter will set that variable to the byte
+length of the resultant string (these are macros, so don't use C<&len>).
+
+The forms with C<nolen> in their names indicate they don't have a C<len>
+parameter.  They should be used only when it is known that the PV is a C
+string, terminated by a NUL byte, and without intermediate NUL characters; or
+when you don't care about its length.
+
+The forms with C<const> in their names return S<C<const char *>> so that the
+compiler will hopefully complain if you were to try to modify the contents of
+the string (unless you cast away const yourself).
+
+The other forms return a mutable pointer so that the string is modifiable by
+the caller; this is emphasized for the ones with C<mutable> in their names.
+
+The forms whose name ends in C<x> are the same as the corresponding form
+without the C<x>, but the C<x> form is guaranteed to evaluate C<sv> exactly
+once, with a slight loss of efficiency.  Use this if C<sv> is an expression
+with side effects.
+
+C<SvPVutf8> is like C<SvPV>, but converts C<sv> to UTF-8 first if not already
+UTF-8.  Similiarly, the other forms with C<utf8> in their names correspond to
+their respective forms without.
+
+C<SvPVutf8_or_null> and C<SvPVutf8_or_null_nomg> don't have corresponding
+non-C<utf8> forms.  Instead they are like C<SvPVutf8_nomg>, but when C<sv> is
+undef, they return C<NULL>.
+
+C<SvPVbyte> is like C<SvPV>, but converts C<sv> to byte representation first if
+currently encoded as UTF-8.  If C<sv> cannot be downgraded from UTF-8, it
+croaks.  Similiarly, the other forms with C<byte> in their names correspond to
+their respective forms without.
+
+C<SvPVbyte_or_null> doesn't have a corresponding non-C<byte> form.  Instead it
+is like C<SvPVbyte>, but when C<sv> is undef, it returns C<NULL>.
 
 =for apidoc Am|IV|SvIV|SV* sv
 =for apidoc_item SvIVx
@@ -1632,24 +1753,30 @@ efficient C<SvUV>.
 
 C<SvUV_nomg> is the same as C<SvUV>, but does not perform 'get' magic.
 
-=for apidoc Am|bool|SvTRUE|SV* sv
-Returns a boolean indicating whether Perl would evaluate the SV as true or
-false.  See C<L</SvOK>> for a defined/undefined test.  Handles 'get' magic
-unless the scalar is already C<SvPOK>, C<SvIOK> or C<SvNOK> (the public, not the
-private flags).
+=for apidoc SvTRUE
+=for apidoc_item SvTRUEx
+=for apidoc_item SvTRUE_nomg
+=for apidoc_item SvTRUE_NN
+=for apidoc_item SvTRUE_nomg_NN
+
+These return a boolean indicating whether Perl would evaluate the SV as true or
+false.  See C<L</SvOK>> for a defined/undefined test.
 
-As of Perl 5.32, this is guaranteed to evaluate C<sv> only once.  Prior to that
-release, use C<L</SvTRUEx>> for single evaluation.
+As of Perl 5.32, all are guaranteed to evaluate C<sv> only once.  Prior to that
+release, only C<SvTRUEx> guaranteed single evaluation; now C<SvTRUEx> is
+identical to C<SvTRUE>.
 
-=for apidoc Am|bool|SvTRUE_nomg|SV* sv
-Returns a boolean indicating whether Perl would evaluate the SV as true or
-false.  See C<L</SvOK>> for a defined/undefined test.  Does not handle 'get' magic.
+C<SvTRUE_nomg> and C<TRUE_nomg_NN> do not perform 'get' magic; the others do
+unless the scalar is already C<SvPOK>, C<SvIOK>, or C<SvNOK> (the public, not
+the private flags).
 
-=for apidoc Am|bool|SvTRUEx|SV* sv
-Identical to C<L</SvTRUE>>.  Prior to 5.32, they differed in that only this one
-was guaranteed to evaluate C<sv> only once; in 5.32 they both evaluated it
-once, but C<SvTRUEx> was slightly slower on some platforms; now they are
-identical.
+C<SvTRUE_NN> is like C<L</SvTRUE>>, but C<sv> is assumed to be
+non-null (NN).  If there is a possibility that it is NULL, use plain
+C<SvTRUE>.
+
+C<SvTRUE_nomg_NN> is like C<L</SvTRUE_nomg>>, but C<sv> is assumed to be
+non-null (NN).  If there is a possibility that it is NULL, use plain
+C<SvTRUE_nomg>.
 
 =for apidoc Am|char*|SvPVutf8_force|SV* sv|STRLEN len
 Like C<SvPV_force>, but converts C<sv> to UTF-8 first if necessary.
@@ -1690,26 +1817,6 @@ Like C<SvPVbyte_or_null>, but does not process get magic.
 Like C<SvPV_nolen>, but converts C<sv> to byte representation first if
 necessary.  If the SV cannot be downgraded from UTF-8, this croaks.
 
-=for apidoc Am|char*|SvPVutf8x_force|SV* sv|STRLEN len
-Like C<SvPV_force>, but converts C<sv> to UTF-8 first if necessary.
-Guarantees to evaluate C<sv> only once; use the more efficient C<SvPVutf8_force>
-otherwise.
-
-=for apidoc Am|char*|SvPVutf8x|SV* sv|STRLEN len
-Like C<SvPV>, but converts C<sv> to UTF-8 first if necessary.
-Guarantees to evaluate C<sv> only once; use the more efficient C<SvPVutf8>
-otherwise.
-
-=for apidoc Am|char*|SvPVbytex_force|SV* sv|STRLEN len
-Like C<SvPV_force>, but converts C<sv> to byte representation first if necessary.
-Guarantees to evaluate C<sv> only once; use the more efficient C<SvPVbyte_force>
-otherwise.  If the SV cannot be downgraded from UTF-8, this croaks.
-
-=for apidoc Am|char*|SvPVbytex|SV* sv|STRLEN len
-Like C<SvPV>, but converts C<sv> to byte representation first if necessary.
-Guarantees to evaluate C<sv> only once; use the more efficient C<SvPVbyte>
-otherwise.  If the SV cannot be downgraded from UTF-8, this croaks.
-
 =for apidoc Am|U32|SvIsCOW|SV* sv
 Returns a U32 value indicating whether the SV is Copy-On-Write (either shared
 hash key scalars, or full Copy On Write scalars if 5.9.0 is configured for
@@ -1856,25 +1963,9 @@ scalar.
 #define SvPVutf8x_force(sv, len) sv_pvutf8n_force(sv, &len)
 #define SvPVbytex_force(sv, len) sv_pvbyten_force(sv, &len)
 
-#define SvTRUE(sv)         Perl_SvTRUE(aTHX_ sv)
 #define SvTRUEx(sv)        SvTRUE(sv)
-#define SvTRUE_nomg(sv)    (LIKELY(sv) && SvTRUE_nomg_NN(sv))
-#define SvTRUE_NN(sv)      (SvGETMAGIC(sv), SvTRUE_nomg_NN(sv))
-#define SvTRUE_nomg_NN(sv) (SvTRUE_common(sv, sv_2bool_nomg(sv)))
-
-#define SvTRUE_common(sv,fallback) (			\
-      SvIMMORTAL_INTERP(sv)                             \
-        ? SvIMMORTAL_TRUE(sv)                           \
-    : !SvOK(sv)						\
-	? 0						\
-    : SvPOK(sv)						\
-	? SvPVXtrue(sv)					\
-    : SvIOK(sv)                			        \
-        ? (SvIVX(sv) != 0 /* cast to bool */)           \
-    : (SvROK(sv) && !(   SvOBJECT(SvRV(sv))             \
-                      && HvAMAGIC(SvSTASH(SvRV(sv)))))  \
-        ? TRUE                                          \
-    : (fallback))
+#define SvTRUEx_nomg(sv)   SvTRUE_nomg(sv)
+#define SvTRUE_nomg_NN(sv) SvTRUE_common(sv, TRUE)
 
 #if defined(PERL_USE_GCC_BRACE_GROUPS)
 
@@ -1888,7 +1979,6 @@ scalar.
 #  define SvPVutf8x(sv, len) ({SV *_sv = (sv); SvPVutf8(_sv, len); })
 #  define SvPVbytex(sv, len) ({SV *_sv = (sv); SvPVbyte(_sv, len); })
 #  define SvPVbytex_nolen(sv) ({SV *_sv = (sv); SvPVbyte_nolen(_sv); })
-#  define SvTRUEx_nomg(sv) ({SV *_sv = (sv); SvTRUE_nomg(_sv); })
 
 #else /* __GNUC__ */
 
@@ -1905,7 +1995,6 @@ scalar.
 #  define SvPVutf8x(sv, len) ((PL_Sv = (sv)), SvPVutf8(PL_Sv, len))
 #  define SvPVbytex(sv, len) ((PL_Sv = (sv)), SvPVbyte(PL_Sv, len))
 #  define SvPVbytex_nolen(sv) ((PL_Sv = (sv)), SvPVbyte_nolen(PL_Sv))
-#  define SvTRUEx_nomg(sv) ((PL_Sv = (sv)), SvTRUE_nomg(PL_Sv))
 #endif /* __GNU__ */
 
 #define SvPVXtrue(sv)	(					\
@@ -1926,6 +2015,12 @@ scalar.
 
 #define SvSHARED_HEK_FROM_PV(pvx) \
 	((struct hek*)(pvx - STRUCT_OFFSET(struct hek, hek_key)))
+/*
+=for apidoc Am|struct hek*|SvSHARED_HASH|SV * sv
+Returns the hash for C<sv> created by C<L</newSVpvn_share>>.
+
+=cut
+*/
 #define SvSHARED_HASH(sv) (0 + SvSHARED_HEK_FROM_PV(SvPVX_const(sv))->hek_hash)
 
 /* flag values for sv_*_flags functions */
@@ -2085,10 +2180,11 @@ scalar.
 #endif
 
 /*
-=for apidoc Am|SV*|newRV_inc|SV* sv
+=for apidoc newRV
+=for apidoc_item ||newRV_inc|
 
-Creates an RV wrapper for an SV.  The reference count for the original SV is
-incremented.
+These are identical.  They create an RV wrapper for an SV.  The reference count
+for the original SV is incremented.
 
 =cut
 */
@@ -2098,7 +2194,7 @@ incremented.
 /* the following macros update any magic values this C<sv> is associated with */
 
 /*
-=for apidoc_section $magic
+=for apidoc_section $SV
 
 =for apidoc Am|void|SvGETMAGIC|SV* sv
 Invokes C<L</mg_get>> on an SV if it has 'get' magic.  For example, this
@@ -2112,18 +2208,21 @@ or a tied variable (it calls C<STORE>).  This macro evaluates its
 argument more than once.
 
 =for apidoc Am|void|SvSetSV|SV* dsv|SV* ssv
-Calls C<sv_setsv> if C<dsv> is not the same as C<ssv>.  May evaluate arguments
-more than once.  Does not handle 'set' magic on the destination SV.
+=for apidoc_item SvSetMagicSV
+=for apidoc_item SvSetSV_nosteal
+=for apidoc_item SvSetMagicSV_nosteal
+
+if C<dsv> is the same as C<ssv>, these do nothing.  Otherwise they all call
+some form of C<L</sv_setsv>>.  They may evaluate their arguments more than
+once.
 
-=for apidoc Am|void|SvSetSV_nosteal|SV* dsv|SV* ssv
-Calls a non-destructive version of C<sv_setsv> if C<dsv> is not the same as
-C<ssv>.  May evaluate arguments more than once.
+The only differences are:
 
-=for apidoc Am|void|SvSetMagicSV|SV* dsv|SV* ssv
-Like C<SvSetSV>, but does any set magic required afterwards.
+C<SvSetMagicSV> and C<SvSetMagicSV_nosteal> perform any required 'set' magic
+afterwards on the destination SV; C<SvSetSV> and C<SvSetSV_nosteal> do not.
 
-=for apidoc Am|void|SvSetMagicSV_nosteal|SV* dsv|SV* ssv
-Like C<SvSetSV_nosteal>, but does any set magic required afterwards.
+C<SvSetSV_nosteal> C<SvSetMagicSV_nosteal> call a non-destructive version of
+C<sv_setsv>.
 
 =for apidoc Am|void|SvSHARE|SV* sv
 Arranges for C<sv> to be shared between threads if a suitable module