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[PATCH] Add string_view support to COW std::string
- From: Jonathan Wakely <jwakely at redhat dot com>
- To: libstdc++ at gcc dot gnu dot org, gcc-patches at gcc dot gnu dot org
- Date: Fri, 13 Jan 2017 15:53:14 +0000
- Subject: [PATCH] Add string_view support to COW std::string
- Authentication-results: sourceware.org; auth=none
This adds the C++17 changes to make std::string_view interoperate with
std::string. The code is mostly just copied from the new std::string,
with two adjustments needed where the names of internal member
functions differ.
With this we have no more test failures when using the old ABI (either
via running tests with -D_GLIBCXX_USE_CXX11_ABI=0 or when configured
so that's the default).
PR libstdc++/79075
* include/bits/basic_string.h [_GLIBCXX_USE_CXX11_ABI] (basic_string):
Make _If_sv private.
[!_GLIBCXX_USE_CXX11_ABI] (basic_string): Add member functions taking
basic_string_view arguments.
Tested powerpc64le-linux, committed to trunk.
commit 587d97a197fdb2216861a80c04ad70e0d7cef14a
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Fri Jan 13 15:26:46 2017 +0000
Add string_view support to COW std::string
PR libstdc++/79075
* include/bits/basic_string.h [_GLIBCXX_USE_CXX11_ABI] (basic_string):
Make _If_sv private.
[!_GLIBCXX_USE_CXX11_ABI] (basic_string): Add member functions taking
basic_string_view arguments.
diff --git a/libstdc++-v3/include/bits/basic_string.h b/libstdc++-v3/include/bits/basic_string.h
index fe8f7e6..9dffcf9 100644
--- a/libstdc++-v3/include/bits/basic_string.h
+++ b/libstdc++-v3/include/bits/basic_string.h
@@ -111,6 +111,12 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
#if __cplusplus > 201402L
// A helper type for avoiding boiler-plate.
typedef basic_string_view<_CharT, _Traits> __sv_type;
+
+ template<typename _Tp, typename _Res>
+ using _If_sv = enable_if_t<
+ __and_<is_convertible<const _Tp&, __sv_type>,
+ __not_<is_convertible<const _Tp&, const _CharT*>>>::value,
+ _Res>;
#endif
// Use empty-base optimization: http://www.cantrip.org/emptyopt.html
@@ -585,12 +591,6 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
{ _M_construct(__beg, __end); }
#if __cplusplus > 201402L
- template<typename _Tp, typename _Res>
- using _If_sv = enable_if_t<
- __and_<is_convertible<const _Tp&, __sv_type>,
- __not_<is_convertible<const _Tp&, const _CharT*>>>::value,
- _Res>;
-
/**
* @brief Construct string from a substring of a string_view.
* @param __t Source string view.
@@ -3320,6 +3320,17 @@ _GLIBCXX_END_NAMESPACE_CXX11
_S_empty_rep() _GLIBCXX_NOEXCEPT
{ return _Rep::_S_empty_rep(); }
+#if __cplusplus > 201402L
+ // A helper type for avoiding boiler-plate.
+ typedef basic_string_view<_CharT, _Traits> __sv_type;
+
+ template<typename _Tp, typename _Res>
+ using _If_sv = enable_if_t<
+ __and_<is_convertible<const _Tp&, __sv_type>,
+ __not_<is_convertible<const _Tp&, const _CharT*>>>::value,
+ _Res>;
+#endif
+
public:
// Construct/copy/destroy:
// NB: We overload ctors in some cases instead of using default
@@ -3441,6 +3452,29 @@ _GLIBCXX_END_NAMESPACE_CXX11
basic_string(_InputIterator __beg, _InputIterator __end,
const _Alloc& __a = _Alloc());
+#if __cplusplus > 201402L
+ /**
+ * @brief Construct string from a substring of a string_view.
+ * @param __t Source string view.
+ * @param __pos The index of the first character to copy from __t.
+ * @param __n The number of characters to copy from __t.
+ * @param __a Allocator to use.
+ */
+ template<typename _Tp, typename = _If_sv<_Tp, void>>
+ basic_string(const _Tp& __t, size_type __pos, size_type __n,
+ const _Alloc& __a = _Alloc())
+ : basic_string(__sv_type(__t).substr(__pos, __n), __a) { }
+
+ /**
+ * @brief Construct string from a string_view.
+ * @param __sv Source string view.
+ * @param __a Allocator to use (default is default allocator).
+ */
+ explicit
+ basic_string(__sv_type __sv, const _Alloc& __a = _Alloc())
+ : basic_string(__sv.data(), __sv.size(), __a) { }
+#endif // C++17
+
/**
* @brief Destroy the string instance.
*/
@@ -3506,6 +3540,23 @@ _GLIBCXX_END_NAMESPACE_CXX11
}
#endif // C++11
+#if __cplusplus > 201402L
+ /**
+ * @brief Set value to string constructed from a string_view.
+ * @param __sv A string_view.
+ */
+ basic_string&
+ operator=(__sv_type __sv)
+ { return this->assign(__sv); }
+
+ /**
+ * @brief Convert to a string_view.
+ * @return A string_view.
+ */
+ operator __sv_type() const noexcept
+ { return __sv_type(data(), size()); }
+#endif // C++17
+
// Iterators:
/**
* Returns a read/write iterator that points to the first character in
@@ -3910,6 +3961,17 @@ _GLIBCXX_END_NAMESPACE_CXX11
{ return this->append(__l.begin(), __l.size()); }
#endif // C++11
+#if __cplusplus > 201402L
+ /**
+ * @brief Append a string_view.
+ * @param __sv The string_view to be appended.
+ * @return Reference to this string.
+ */
+ basic_string&
+ operator+=(__sv_type __sv)
+ { return this->append(__sv); }
+#endif // C++17
+
/**
* @brief Append a string to this string.
* @param __str The string to append.
@@ -3990,6 +4052,34 @@ _GLIBCXX_END_NAMESPACE_CXX11
append(_InputIterator __first, _InputIterator __last)
{ return this->replace(_M_iend(), _M_iend(), __first, __last); }
+#if __cplusplus > 201402L
+ /**
+ * @brief Append a string_view.
+ * @param __sv The string_view to be appended.
+ * @return Reference to this string.
+ */
+ basic_string&
+ append(__sv_type __sv)
+ { return this->append(__sv.data(), __sv.size()); }
+
+ /**
+ * @brief Append a range of characters from a string_view.
+ * @param __sv The string_view to be appended from.
+ * @param __pos The position in the string_view to append from.
+ * @param __n The number of characters to append from the string_view.
+ * @return Reference to this string.
+ */
+ template <typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ append(const _Tp& __svt, size_type __pos, size_type __n = npos)
+ {
+ __sv_type __sv = __svt;
+ return append(__sv.data()
+ + __sv._M_check(__pos, "basic_string::append"),
+ __sv._M_limit(__pos, __n));
+ }
+#endif // C++17
+
/**
* @brief Append a single character.
* @param __c Character to append.
@@ -4115,6 +4205,34 @@ _GLIBCXX_END_NAMESPACE_CXX11
{ return this->assign(__l.begin(), __l.size()); }
#endif // C++11
+#if __cplusplus > 201402L
+ /**
+ * @brief Set value from a string_view.
+ * @param __sv The source string_view.
+ * @return Reference to this string.
+ */
+ basic_string&
+ assign(__sv_type __sv)
+ { return this->assign(__sv.data(), __sv.size()); }
+
+ /**
+ * @brief Set value from a range of characters in a string_view.
+ * @param __sv The source string_view.
+ * @param __pos The position in the string_view to assign from.
+ * @param __n The number of characters to assign.
+ * @return Reference to this string.
+ */
+ template <typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ assign(const _Tp& __svt, size_type __pos, size_type __n = npos)
+ {
+ __sv_type __sv = __svt;
+ return assign(__sv.data()
+ + __sv._M_check(__pos, "basic_string::assign"),
+ __sv._M_limit(__pos, __n));
+ }
+#endif // C++17
+
/**
* @brief Insert multiple characters.
* @param __p Iterator referencing location in string to insert at.
@@ -4290,6 +4408,38 @@ _GLIBCXX_END_NAMESPACE_CXX11
return iterator(_M_data() + __pos);
}
+#if __cplusplus > 201402L
+ /**
+ * @brief Insert a string_view.
+ * @param __pos Iterator referencing position in string to insert at.
+ * @param __sv The string_view to insert.
+ * @return Reference to this string.
+ */
+ basic_string&
+ insert(size_type __pos, __sv_type __sv)
+ { return this->insert(__pos, __sv.data(), __sv.size()); }
+
+ /**
+ * @brief Insert a string_view.
+ * @param __pos Iterator referencing position in string to insert at.
+ * @param __sv The string_view to insert from.
+ * @param __pos Iterator referencing position in string_view to insert
+ * from.
+ * @param __n The number of characters to insert.
+ * @return Reference to this string.
+ */
+ template <typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ insert(size_type __pos1, const _Tp& __svt,
+ size_type __pos2, size_type __n = npos)
+ {
+ __sv_type __sv = __svt;
+ return this->replace(__pos1, size_type(0), __sv.data()
+ + __sv._M_check(__pos2, "basic_string::insert"),
+ __sv._M_limit(__pos2, __n));
+ }
+#endif // C++17
+
/**
* @brief Remove characters.
* @param __pos Index of first character to remove (default 0).
@@ -4644,6 +4794,52 @@ _GLIBCXX_END_NAMESPACE_CXX11
{ return this->replace(__i1, __i2, __l.begin(), __l.end()); }
#endif // C++11
+#if __cplusplus > 201402L
+ /**
+ * @brief Replace range of characters with string_view.
+ * @param __pos The position to replace at.
+ * @param __n The number of characters to replace.
+ * @param __sv The string_view to insert.
+ * @return Reference to this string.
+ */
+ basic_string&
+ replace(size_type __pos, size_type __n, __sv_type __sv)
+ { return this->replace(__pos, __n, __sv.data(), __sv.size()); }
+
+ /**
+ * @brief Replace range of characters with string_view.
+ * @param __pos1 The position to replace at.
+ * @param __n1 The number of characters to replace.
+ * @param __sv The string_view to insert from.
+ * @param __pos2 The position in the string_view to insert from.
+ * @param __n2 The number of characters to insert.
+ * @return Reference to this string.
+ */
+ template <typename _Tp>
+ _If_sv<_Tp, basic_string&>
+ replace(size_type __pos1, size_type __n1, const _Tp& __svt,
+ size_type __pos2, size_type __n2 = npos)
+ {
+ __sv_type __sv = __svt;
+ return this->replace(__pos1, __n1, __sv.data()
+ + __sv._M_check(__pos2, "basic_string::replace"),
+ __sv._M_limit(__pos2, __n2));
+ }
+
+ /**
+ * @brief Replace range of characters with string_view.
+ * @param __i1 An iterator referencing the start position
+ to replace at.
+ * @param __i2 An iterator referencing the end position
+ for the replace.
+ * @param __sv The string_view to insert from.
+ * @return Reference to this string.
+ */
+ basic_string&
+ replace(const_iterator __i1, const_iterator __i2, __sv_type __sv)
+ { return this->replace(__i1 - begin(), __i2 - __i1, __sv); }
+#endif // C++17
+
private:
template<class _Integer>
basic_string&
@@ -4843,6 +5039,18 @@ _GLIBCXX_END_NAMESPACE_CXX11
size_type
find(_CharT __c, size_type __pos = 0) const _GLIBCXX_NOEXCEPT;
+#if __cplusplus > 201402L
+ /**
+ * @brief Find position of a string_view.
+ * @param __sv The string_view to locate.
+ * @param __pos Index of character to search from (default 0).
+ * @return Index of start of first occurrence.
+ */
+ size_type
+ find(__sv_type __sv, size_type __pos = 0) const noexcept
+ { return this->find(__sv.data(), __pos, __sv.size()); }
+#endif // C++17
+
/**
* @brief Find last position of a string.
* @param __str String to locate.
@@ -4904,6 +5112,18 @@ _GLIBCXX_END_NAMESPACE_CXX11
size_type
rfind(_CharT __c, size_type __pos = npos) const _GLIBCXX_NOEXCEPT;
+#if __cplusplus > 201402L
+ /**
+ * @brief Find last position of a string_view.
+ * @param __sv The string_view to locate.
+ * @param __pos Index of character to search back from (default end).
+ * @return Index of start of last occurrence.
+ */
+ size_type
+ rfind(__sv_type __sv, size_type __pos = npos) const noexcept
+ { return this->rfind(__sv.data(), __pos, __sv.size()); }
+#endif // C++17
+
/**
* @brief Find position of a character of string.
* @param __str String containing characters to locate.
@@ -4970,6 +5190,18 @@ _GLIBCXX_END_NAMESPACE_CXX11
find_first_of(_CharT __c, size_type __pos = 0) const _GLIBCXX_NOEXCEPT
{ return this->find(__c, __pos); }
+#if __cplusplus > 201402L
+ /**
+ * @brief Find position of a character of a string_view.
+ * @param __sv A string_view containing characters to locate.
+ * @param __pos Index of character to search from (default 0).
+ * @return Index of first occurrence.
+ */
+ size_type
+ find_first_of(__sv_type __sv, size_type __pos = 0) const noexcept
+ { return this->find_first_of(__sv.data(), __pos, __sv.size()); }
+#endif // C++17
+
/**
* @brief Find last position of a character of string.
* @param __str String containing characters to locate.
@@ -5036,6 +5268,18 @@ _GLIBCXX_END_NAMESPACE_CXX11
find_last_of(_CharT __c, size_type __pos = npos) const _GLIBCXX_NOEXCEPT
{ return this->rfind(__c, __pos); }
+#if __cplusplus > 201402L
+ /**
+ * @brief Find last position of a character of string.
+ * @param __sv A string_view containing characters to locate.
+ * @param __pos Index of character to search back from (default end).
+ * @return Index of last occurrence.
+ */
+ size_type
+ find_last_of(__sv_type __sv, size_type __pos = npos) const noexcept
+ { return this->find_last_of(__sv.data(), __pos, __sv.size()); }
+#endif // C++17
+
/**
* @brief Find position of a character not in string.
* @param __str String containing characters to avoid.
@@ -5099,6 +5343,18 @@ _GLIBCXX_END_NAMESPACE_CXX11
find_first_not_of(_CharT __c, size_type __pos = 0) const
_GLIBCXX_NOEXCEPT;
+#if __cplusplus > 201402L
+ /**
+ * @brief Find position of a character not in a string_view.
+ * @param __sv A string_view containing characters to avoid.
+ * @param __pos Index of character to search from (default 0).
+ * @return Index of first occurrence.
+ */
+ size_type
+ find_first_not_of(__sv_type __sv, size_type __pos = 0) const noexcept
+ { return this->find_first_not_of(__sv.data(), __pos, __sv.size()); }
+#endif // C++17
+
/**
* @brief Find last position of a character not in string.
* @param __str String containing characters to avoid.
@@ -5163,6 +5419,18 @@ _GLIBCXX_END_NAMESPACE_CXX11
find_last_not_of(_CharT __c, size_type __pos = npos) const
_GLIBCXX_NOEXCEPT;
+#if __cplusplus > 201402L
+ /**
+ * @brief Find last position of a character not in a string_view.
+ * @param __sv A string_view containing characters to avoid.
+ * @param __pos Index of character to search back from (default end).
+ * @return Index of last occurrence.
+ */
+ size_type
+ find_last_not_of(__sv_type __sv, size_type __pos = npos) const noexcept
+ { return this->find_last_not_of(__sv.data(), __pos, __sv.size()); }
+#endif // C++17
+
/**
* @brief Get a substring.
* @param __pos Index of first character (default 0).
@@ -5207,6 +5475,56 @@ _GLIBCXX_END_NAMESPACE_CXX11
return __r;
}
+#if __cplusplus > 201402L
+ /**
+ * @brief Compare to a string_view.
+ * @param __sv A string_view to compare against.
+ * @return Integer < 0, 0, or > 0.
+ */
+ int
+ compare(__sv_type __sv) const
+ {
+ const size_type __size = this->size();
+ const size_type __osize = __sv.size();
+ const size_type __len = std::min(__size, __osize);
+
+ int __r = traits_type::compare(_M_data(), __sv.data(), __len);
+ if (!__r)
+ __r = _S_compare(__size, __osize);
+ return __r;
+ }
+
+ /**
+ * @brief Compare to a string_view.
+ * @param __pos A position in the string to start comparing from.
+ * @param __n The number of characters to compare.
+ * @param __sv A string_view to compare against.
+ * @return Integer < 0, 0, or > 0.
+ */
+ int
+ compare(size_type __pos, size_type __n, __sv_type __sv) const
+ { return __sv_type(*this).substr(__pos, __n).compare(__sv); }
+
+ /**
+ * @brief Compare to a string_view.
+ * @param __pos1 A position in the string to start comparing from.
+ * @param __n1 The number of characters to compare.
+ * @param __sv A string_view to compare against.
+ * @param __pos2 A position in the string_view to start comparing from.
+ * @param __n2 The number of characters to compare.
+ * @return Integer < 0, 0, or > 0.
+ */
+ template <typename _Tp>
+ _If_sv<_Tp, int>
+ compare(size_type __pos1, size_type __n1, const _Tp& __svt,
+ size_type __pos2, size_type __n2 = npos) const
+ {
+ __sv_type __sv = __svt;
+ return __sv_type(*this)
+ .substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2));
+ }
+#endif // C++17
+
/**
* @brief Compare substring to a string.
* @param __pos Index of first character of substring.