zstring_view: Fix coercion
This ensures that types are correctly coerced to zstring_views and not
implicitly converted.
Change-Id: Ic9340c5fbf5f5d0f8890406601202790f53e6eb6
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/include/stdplus/zstring_view.hpp b/include/stdplus/zstring_view.hpp
index 782af2e..babb1c2 100644
--- a/include/stdplus/zstring_view.hpp
+++ b/include/stdplus/zstring_view.hpp
@@ -27,6 +27,19 @@
}
template <typename CharT, std::size_t N>
+constexpr bool zstring_validate(const CharT (&str)[N]) noexcept
+{
+ for (size_t i = 0; i < N - 1; ++i)
+ {
+ if (str[i] == '\0')
+ {
+ return false;
+ }
+ }
+ return str[N - 1] == '\0';
+}
+
+template <typename CharT, std::size_t N>
struct compile_zstring_view
{
CharT data[N] = {};
@@ -34,18 +47,11 @@
constexpr compile_zstring_view(const CharT (&str)[N]) noexcept
{
- for (size_t i = 0; i < N - 1; ++i)
+ valid = zstring_validate(str);
+ for (std::size_t i = 0; i < N - 1; ++i)
{
- if (str[i] == '\0')
- {
- valid = false;
- }
data[i] = str[i];
}
- if (str[N - 1] != '\0')
- {
- valid = false;
- }
}
constexpr auto getzsv() const noexcept
@@ -78,18 +84,47 @@
static constexpr size_type npos = string_view_base::npos;
- inline constexpr basic_zstring_view(const_pointer str) noexcept : sv(str)
+ template <
+ typename T, size_type N,
+ std::enable_if_t<std::is_same_v<value_type, std::remove_cvref_t<T>>,
+ bool> = true>
+ constexpr basic_zstring_view(T (&str)[N])
+#ifdef NDEBUG
+ noexcept
+#endif
+ :
+ sv(str, N - 1)
{
- }
- template <typename Allocator>
- constexpr basic_zstring_view(
- const std::basic_string<CharT, Traits, Allocator>& str) :
- sv(str)
- {
- if (sv.find('\0') != npos)
+#ifndef NDEBUG
+ if (!detail::zstring_validate(str))
{
throw std::invalid_argument("stdplus::zstring_view");
}
+#endif
+ }
+ template <typename T, std::enable_if_t<std::is_pointer_v<T>, bool> = true>
+ inline constexpr basic_zstring_view(T str) noexcept : sv(str)
+ {
+ }
+ template <typename T,
+ std::enable_if_t<
+ std::is_same_v<std::basic_string<value_type, Traits,
+ typename T::allocator_type>,
+ std::remove_cvref_t<T>>,
+ bool> = true>
+ constexpr basic_zstring_view(T& str)
+#ifdef NDEBUG
+ noexcept
+#endif
+ :
+ sv(str.data())
+ {
+#ifndef NDEBUG
+ if (str.find('\0') != npos)
+ {
+ throw std::invalid_argument("stdplus::zstring_view");
+ }
+#endif
}
inline constexpr operator string_view_base() const noexcept
@@ -256,6 +291,28 @@
return basic_zstring_view(unsafe(), sv.substr(pos));
}
+ template <typename CharTO, size_type N>
+ inline constexpr bool operator==(const CharTO (&rhs)[N]) const noexcept
+ {
+ return *this == std::basic_string_view<CharTO, Traits>(rhs, N - 1);
+ }
+ constexpr bool
+ operator==(std::basic_string_view<CharT, Traits> rhs) const noexcept
+ {
+ return size() == rhs.size() && compare(rhs) == 0;
+ }
+ template <typename CharTO, size_type N>
+ inline constexpr Traits::comparison_category
+ operator<=>(const CharTO (&rhs)[N]) const noexcept
+ {
+ return *this <=> std::basic_string_view<CharTO, Traits>(rhs, N - 1);
+ }
+ constexpr Traits::comparison_category
+ operator<=>(std::basic_string_view<CharT, Traits> rhs) const noexcept
+ {
+ return compare(rhs) <=> 0;
+ }
+
private:
string_view_base sv;
@@ -269,49 +326,6 @@
friend auto detail::unsafe_zstring_view<CharT, Traits>(string_view_base sv);
};
-template <class CharT, class Traits>
-constexpr bool operator==(basic_zstring_view<CharT, Traits> lhs,
- basic_zstring_view<CharT, Traits> rhs) noexcept
-{
- return lhs.size() == rhs.size() && lhs.compare(rhs) == 0;
-}
-template <class CharT, class Traits>
-constexpr bool operator==(
- basic_zstring_view<CharT, Traits> lhs,
- std::type_identity_t<std::basic_string_view<CharT, Traits>> rhs) noexcept
-{
- return lhs.size() == rhs.size() && lhs.compare(rhs) == 0;
-}
-template <class CharT, class Traits>
-constexpr bool
- operator==(std::type_identity_t<std::basic_string_view<CharT, Traits>> lhs,
- basic_zstring_view<CharT, Traits> rhs) noexcept
-{
- return lhs.size() == rhs.size() && lhs.compare(rhs) == 0;
-}
-
-template <class CharT, class Traits>
-constexpr Traits::comparison_category
- operator<=>(basic_zstring_view<CharT, Traits> lhs,
- basic_zstring_view<CharT, Traits> rhs) noexcept
-{
- return lhs.compare(rhs) <=> 0;
-}
-template <class CharT, class Traits>
-constexpr Traits::comparison_category operator<=>(
- basic_zstring_view<CharT, Traits> lhs,
- std::type_identity_t<std::basic_string_view<CharT, Traits>> rhs) noexcept
-{
- return lhs.compare(rhs) <=> 0;
-}
-template <class CharT, class Traits>
-constexpr Traits::comparison_category
- operator<=>(std::type_identity_t<std::basic_string_view<CharT, Traits>> lhs,
- basic_zstring_view<CharT, Traits> rhs) noexcept
-{
- return lhs.compare(rhs) <=> 0;
-}
-
template <typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>&
operator<<(std::basic_ostream<CharT, Traits>& os,
@@ -332,7 +346,7 @@
} // namespace stdplus
-#define zstring_all(char_t, pfx) \
+#define zstring_view_all(char_t, pfx) \
namespace stdplus \
{ \
using pfx##zstring_view = basic_zstring_view<char_t>; \
@@ -345,9 +359,9 @@
{ \
}; \
}
-zstring_all(char, );
-zstring_all(char8_t, u8);
-zstring_all(char16_t, u16);
-zstring_all(char32_t, u32);
-zstring_all(wchar_t, w);
-#undef zstring_all
+zstring_view_all(char, );
+zstring_view_all(char8_t, u8);
+zstring_view_all(char16_t, u16);
+zstring_view_all(char32_t, u32);
+zstring_view_all(wchar_t, w);
+#undef zstring_view_all
diff --git a/test/zstring_view.cpp b/test/zstring_view.cpp
index 1b7120d..8ed2f63 100644
--- a/test/zstring_view.cpp
+++ b/test/zstring_view.cpp
@@ -18,9 +18,12 @@
auto s = "b"s;
auto s2 = zstring_view(s);
std::string_view sv = s1;
+ char mut[] = "aa";
+ auto s3 = zstring_view(mut);
EXPECT_NE(sv, s2);
EXPECT_NE(s1, s2);
+ EXPECT_EQ(s3, "aa");
EXPECT_EQ("ac"_zsv, s1);
EXPECT_EQ("ac", s1);
@@ -50,7 +53,21 @@
TEST(ZstringView, ConstructError)
{
auto s = "hi\0"s;
+#ifdef NDEBUG
+ EXPECT_EQ("hi", zstring_view(s));
+#else
EXPECT_THROW((zstring_view(s)), std::invalid_argument);
+#endif
+
+ char mut1[] = "aa\0";
+ char mut2[] = {'a', 'a'};
+#ifdef NDEBUG
+ EXPECT_EQ("aa\0", zstring_view(mut1));
+ EXPECT_EQ("a", zstring_view(mut2));
+#else
+ EXPECT_THROW((zstring_view(mut1)), std::invalid_argument);
+ EXPECT_THROW((zstring_view(mut2)), std::invalid_argument);
+#endif
}
TEST(ZstringView, Suffix)
@@ -65,6 +82,8 @@
TEST(ZstringView, NoTypeCoercion)
{
+ EXPECT_NE(""_zsv, "\0");
+ EXPECT_NE("\0", ""_zsv);
EXPECT_NE(""_zsv, "\0"sv);
EXPECT_NE("\0"sv, ""_zsv);
EXPECT_LT(""_zsv, "\0"sv);