Ask associated streambuf for character when needed instead of
accumulate it in istreambuf_iterator object.
Benefits from this:
- minus one class member in istreambuf_iterator
- trivial synchronization of states of istreambuf_iterator
and associated streambuf
---
libstdc++-v3/include/bits/streambuf_iterator.h | 34 ++++++++++++--------------
1 file changed, 15 insertions(+), 19 deletions(-)
diff --git a/libstdc++-v3/include/bits/streambuf_iterator.h
b/libstdc++-v3/include/bits/streambuf_iterator.h
index 08fb13b..203da9d 100644
--- a/libstdc++-v3/include/bits/streambuf_iterator.h
+++ b/libstdc++-v3/include/bits/streambuf_iterator.h
@@ -95,19 +95,18 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// NB: This implementation assumes the "end of stream" value
// is EOF, or -1.
mutable streambuf_type* _M_sbuf;
- mutable int_type _M_c;
public:
class proxy
{
friend class istreambuf_iterator;
private:
- proxy(int_type c, streambuf_type* sbuf_) :
+ proxy(int_type c, streambuf_type* sbuf_) :
_M_c(c),
_M_sbuf(sbuf_)
{ }
int_type _M_c;
- streambuf_type* _M_sbuf;
+ streambuf_type* _M_sbuf;
public:
char_type
@@ -118,7 +117,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
public:
/// Construct end of input stream iterator.
_GLIBCXX_CONSTEXPR istreambuf_iterator() _GLIBCXX_USE_NOEXCEPT
- : _M_sbuf(0), _M_c(traits_type::eof()) { }
+ : _M_sbuf(0) { }
#if __cplusplus >= 201103L
istreambuf_iterator(const istreambuf_iterator&) noexcept = default;
@@ -128,15 +127,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
/// Construct start of input stream iterator.
istreambuf_iterator(istream_type& __s) _GLIBCXX_USE_NOEXCEPT
- : _M_sbuf(__s.rdbuf()), _M_c(traits_type::eof()) { }
+ : _M_sbuf(__s.rdbuf()) { }
/// Construct start of streambuf iterator.
istreambuf_iterator(streambuf_type* __s) _GLIBCXX_USE_NOEXCEPT
- : _M_sbuf(__s), _M_c(traits_type::eof()) { }
+ : _M_sbuf(__s) { }
/// Construct start of istreambuf iterator.
istreambuf_iterator(const proxy& __p) _GLIBCXX_USE_NOEXCEPT
- : _M_sbuf(__p._M_sbuf), _M_c(traits_type::eof()) { }
+ : _M_sbuf(__p._M_sbuf) { }
/// Return the current character pointed to by iterator. This returns
/// streambuf.sgetc(). It cannot be assigned. NB: The result of
@@ -147,11 +146,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
#ifdef _GLIBCXX_DEBUG_PEDANTIC
// Dereferencing a past-the-end istreambuf_iterator is a
// libstdc++ extension
- __glibcxx_requires_cond(!_M_at_eof(),
+ int_type __tmp = _M_get();
+
__glibcxx_requires_cond(!traits_type::eq_int_type(__tmp,traits_type::eof()),
_M_message(__gnu_debug::__msg_deref_istreambuf)
._M_iterator(*this));
-#endif
+ return traits_type::to_char_type(__tmp);
+#else
return traits_type::to_char_type(_M_get());
+#endif
}
/// Advance the iterator. Calls streambuf.sbumpc().
@@ -172,7 +174,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_M_message(__gnu_debug::__msg_inc_istreambuf)
._M_iterator(*this));
#endif
- _M_c = traits_type::eof();
}
return *this;
}
@@ -181,17 +182,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
proxy
operator++(int)
{
- _M_get();
- __glibcxx_requires_cond(_M_sbuf
- &&
!traits_type::eq_int_type(_M_c,traits_type::eof()),
+ int_type c = _M_get();
+ __glibcxx_requires_cond(!traits_type::eq_int_type(c,traits_type::eof()),
_M_message(__gnu_debug::__msg_inc_istreambuf)
._M_iterator(*this));
- proxy __old(_M_c, _M_sbuf);
+ proxy __old(c, _M_sbuf);
if (_M_sbuf)
{
_M_sbuf->sbumpc();
- _M_c = traits_type::eof();
}
return __old;
}
@@ -209,9 +208,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_M_get() const
{
const int_type __eof = traits_type::eof();
- if (_M_sbuf && traits_type::eq_int_type(_M_c, __eof))
- _M_c = _M_sbuf->sgetc();
- return _M_c;
+ return _M_sbuf ? _M_sbuf->sgetc() : __eof;
}
bool
@@ -418,7 +415,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
else
__c = __sb->snextc();
}
- __first._M_c = __c;
}
return __first;
}
--
2.10.1
