dep: Add rapidyaml

dep/rapidyaml/include/c4/std/vector.hpp

@@ -0,0 +1,88 @@
+#ifndef _C4_STD_VECTOR_HPP_
+#define _C4_STD_VECTOR_HPP_
+
+/** @file vector.hpp provides conversion and comparison facilities
+ * from/between std::vector<char> to c4::substr and c4::csubstr.
+ * @todo add to_span() and friends
+ */
+
+#ifndef C4CORE_SINGLE_HEADER
+#include "c4/substr.hpp"
+#endif
+
+#include <vector>
+
+namespace c4 {
+
+//-----------------------------------------------------------------------------
+
+/** get a substr (writeable string view) of an existing std::vector<char> */
+template<class Alloc>
+c4::substr to_substr(std::vector<char, Alloc> &vec)
+{
+    char *data = vec.empty() ? nullptr : vec.data(); // data() may or may not return a null pointer.
+    return c4::substr(data, vec.size());
+}
+
+/** get a csubstr (read-only string) view of an existing std::vector<char> */
+template<class Alloc>
+c4::csubstr to_csubstr(std::vector<char, Alloc> const& vec)
+{
+    const char *data = vec.empty() ? nullptr : vec.data(); // data() may or may not return a null pointer.
+    return c4::csubstr(data, vec.size());
+}
+
+//-----------------------------------------------------------------------------
+// comparisons between substrings and std::vector<char>
+
+template<class Alloc> C4_ALWAYS_INLINE bool operator!= (c4::csubstr ss, std::vector<char, Alloc> const& s) { return ss != to_csubstr(s); }
+template<class Alloc> C4_ALWAYS_INLINE bool operator== (c4::csubstr ss, std::vector<char, Alloc> const& s) { return ss == to_csubstr(s); }
+template<class Alloc> C4_ALWAYS_INLINE bool operator>= (c4::csubstr ss, std::vector<char, Alloc> const& s) { return ss >= to_csubstr(s); }
+template<class Alloc> C4_ALWAYS_INLINE bool operator>  (c4::csubstr ss, std::vector<char, Alloc> const& s) { return ss >  to_csubstr(s); }
+template<class Alloc> C4_ALWAYS_INLINE bool operator<= (c4::csubstr ss, std::vector<char, Alloc> const& s) { return ss <= to_csubstr(s); }
+template<class Alloc> C4_ALWAYS_INLINE bool operator<  (c4::csubstr ss, std::vector<char, Alloc> const& s) { return ss <  to_csubstr(s); }
+
+template<class Alloc> C4_ALWAYS_INLINE bool operator!= (std::vector<char, Alloc> const& s, c4::csubstr ss) { return ss != to_csubstr(s); }
+template<class Alloc> C4_ALWAYS_INLINE bool operator== (std::vector<char, Alloc> const& s, c4::csubstr ss) { return ss == to_csubstr(s); }
+template<class Alloc> C4_ALWAYS_INLINE bool operator>= (std::vector<char, Alloc> const& s, c4::csubstr ss) { return ss <= to_csubstr(s); }
+template<class Alloc> C4_ALWAYS_INLINE bool operator>  (std::vector<char, Alloc> const& s, c4::csubstr ss) { return ss <  to_csubstr(s); }
+template<class Alloc> C4_ALWAYS_INLINE bool operator<= (std::vector<char, Alloc> const& s, c4::csubstr ss) { return ss >= to_csubstr(s); }
+template<class Alloc> C4_ALWAYS_INLINE bool operator<  (std::vector<char, Alloc> const& s, c4::csubstr ss) { return ss >  to_csubstr(s); }
+
+//-----------------------------------------------------------------------------
+
+/** copy a std::vector<char> to a writeable string view */
+template<class Alloc>
+inline size_t to_chars(c4::substr buf, std::vector<char, Alloc> const& s)
+{
+    C4_ASSERT(!buf.overlaps(to_csubstr(s)));
+    size_t len = buf.len < s.size() ? buf.len : s.size();
+    // calling memcpy with null strings is undefined behavior
+    // and will wreak havoc in calling code's branches.
+    // see https://github.com/biojppm/rapidyaml/pull/264#issuecomment-1262133637
+    if(len > 0)
+    {
+        memcpy(buf.str, s.data(), len);
+    }
+    return s.size(); // return the number of needed chars
+}
+
+/** copy a string view to an existing std::vector<char> */
+template<class Alloc>
+inline bool from_chars(c4::csubstr buf, std::vector<char, Alloc> * s)
+{
+    s->resize(buf.len);
+    C4_ASSERT(!buf.overlaps(to_csubstr(*s)));
+    // calling memcpy with null strings is undefined behavior
+    // and will wreak havoc in calling code's branches.
+    // see https://github.com/biojppm/rapidyaml/pull/264#issuecomment-1262133637
+    if(buf.len > 0)
+    {
+        memcpy(&(*s)[0], buf.str, buf.len);
+    }
+    return true;
+}
+
+} // namespace c4
+
+#endif // _C4_STD_VECTOR_HPP_