Remove cause of "whitespace in literal operator" warning in Clang 20 (#61, thanks @striezel)

When string-view lite is compiled with Clang 20, it emits the
following deprecation warnings:

    /__w/string-view-lite/string-view-lite/include/nonstd/string_view.hpp:1539:57: warning: identifier '_sv' preceded by whitespace in a literal operator declaration is deprecated [-Wdeprecated-literal-operator]
     1539 | nssv_constexpr nonstd::sv_lite::string_view operator "" _sv( const char* str, size_t len ) nssv_noexcept  // (1)
          |                                             ~~~~~~~~~~~~^~~
          |                                             operator""_sv
    /__w/string-view-lite/string-view-lite/include/nonstd/string_view.hpp:1544:60: warning: identifier '_sv' preceded by whitespace in a literal operator declaration is deprecated [-Wdeprecated-literal-operator]
     1544 | nssv_constexpr nonstd::sv_lite::u16string_view operator "" _sv( const char16_t* str, size_t len ) nssv_noexcept  // (2)
          |                                                ~~~~~~~~~~~~^~~
          |                                                operator""_sv
    /__w/string-view-lite/string-view-lite/include/nonstd/string_view.hpp:1549:60: warning: identifier '_sv' preceded by whitespace in a literal operator declaration is deprecated [-Wdeprecated-literal-operator]
     1549 | nssv_constexpr nonstd::sv_lite::u32string_view operator "" _sv( const char32_t* str, size_t len ) nssv_noexcept  // (3)
          |                                                ~~~~~~~~~~~~^~~
          |                                                operator""_sv
    /__w/string-view-lite/string-view-lite/include/nonstd/string_view.hpp:1554:58: warning: identifier '_sv' preceded by whitespace in a literal operator declaration is deprecated [-Wdeprecated-literal-operator]
     1554 | nssv_constexpr nonstd::sv_lite::wstring_view operator "" _sv( const wchar_t* str, size_t len ) nssv_noexcept  // (4)
          |                                              ~~~~~~~~~~~~^~~
          |                                              operator""_sv

To fix that problem the space characters in the literal operator declarations are removed.

Author: striezel

include/nonstd/string_view.hpp

@@ -166,22 +166,22 @@ inline namespace literals {
 inline namespace string_view_literals {
 
 
-constexpr std::string_view operator "" _sv( const char* str, size_t len ) noexcept  // (1)
+constexpr std::string_view operator""_sv( const char* str, size_t len ) noexcept  // (1)
 {
     return std::string_view{ str, len };
 }
 
-constexpr std::u16string_view operator "" _sv( const char16_t* str, size_t len ) noexcept  // (2)
+constexpr std::u16string_view operator""_sv( const char16_t* str, size_t len ) noexcept  // (2)
 {
     return std::u16string_view{ str, len };
 }
 
-constexpr std::u32string_view operator "" _sv( const char32_t* str, size_t len ) noexcept  // (3)
+constexpr std::u32string_view operator""_sv( const char32_t* str, size_t len ) noexcept  // (3)
 {
     return std::u32string_view{ str, len };
 }
 
-constexpr std::wstring_view operator "" _sv( const wchar_t* str, size_t len ) noexcept  // (4)
+constexpr std::wstring_view operator""_sv( const wchar_t* str, size_t len ) noexcept  // (4)
 {
     return std::wstring_view{ str, len };
 }
@@ -1512,22 +1512,22 @@ nssv_inline_ns namespace string_view_literals {
 
 #if nssv_CONFIG_STD_SV_OPERATOR && nssv_HAVE_STD_DEFINED_LITERALS
 
-nssv_constexpr nonstd::sv_lite::string_view operator "" sv( const char* str, size_t len ) nssv_noexcept  // (1)
+nssv_constexpr nonstd::sv_lite::string_view operator""sv( const char* str, size_t len ) nssv_noexcept  // (1)
 {
     return nonstd::sv_lite::string_view{ str, len };
 }
 
-nssv_constexpr nonstd::sv_lite::u16string_view operator "" sv( const char16_t* str, size_t len ) nssv_noexcept  // (2)
+nssv_constexpr nonstd::sv_lite::u16string_view operator""sv( const char16_t* str, size_t len ) nssv_noexcept  // (2)
 {
     return nonstd::sv_lite::u16string_view{ str, len };
 }
 
-nssv_constexpr nonstd::sv_lite::u32string_view operator "" sv( const char32_t* str, size_t len ) nssv_noexcept  // (3)
+nssv_constexpr nonstd::sv_lite::u32string_view operator""sv( const char32_t* str, size_t len ) nssv_noexcept  // (3)
 {
     return nonstd::sv_lite::u32string_view{ str, len };
 }
 
-nssv_constexpr nonstd::sv_lite::wstring_view operator "" sv( const wchar_t* str, size_t len ) nssv_noexcept  // (4)
+nssv_constexpr nonstd::sv_lite::wstring_view operator""sv( const wchar_t* str, size_t len ) nssv_noexcept  // (4)
 {
     return nonstd::sv_lite::wstring_view{ str, len };
 }
@@ -1536,22 +1536,22 @@ nssv_constexpr nonstd::sv_lite::wstring_view operator "" sv( const wchar_t* str,
 
 #if nssv_CONFIG_USR_SV_OPERATOR
 
-nssv_constexpr nonstd::sv_lite::string_view operator "" _sv( const char* str, size_t len ) nssv_noexcept  // (1)
+nssv_constexpr nonstd::sv_lite::string_view operator""_sv( const char* str, size_t len ) nssv_noexcept  // (1)
 {
     return nonstd::sv_lite::string_view{ str, len };
 }
 
-nssv_constexpr nonstd::sv_lite::u16string_view operator "" _sv( const char16_t* str, size_t len ) nssv_noexcept  // (2)
+nssv_constexpr nonstd::sv_lite::u16string_view operator""_sv( const char16_t* str, size_t len ) nssv_noexcept  // (2)
 {
     return nonstd::sv_lite::u16string_view{ str, len };
 }
 
-nssv_constexpr nonstd::sv_lite::u32string_view operator "" _sv( const char32_t* str, size_t len ) nssv_noexcept  // (3)
+nssv_constexpr nonstd::sv_lite::u32string_view operator""_sv( const char32_t* str, size_t len ) nssv_noexcept  // (3)
 {
     return nonstd::sv_lite::u32string_view{ str, len };
 }
 
-nssv_constexpr nonstd::sv_lite::wstring_view operator "" _sv( const wchar_t* str, size_t len ) nssv_noexcept  // (4)
+nssv_constexpr nonstd::sv_lite::wstring_view operator""_sv( const wchar_t* str, size_t len ) nssv_noexcept  // (4)
 {
     return nonstd::sv_lite::wstring_view{ str, len };
 }