Added CellStringReference::getRequiredBufferSize() to make compile-ti…

…me buffer creation easier.

README.md

@@ -148,7 +148,7 @@ static_assert(matrix[1][1].getOriginalStringView() == "6"sv);
 // buffer to place the clean string inside. The buffer size has to be at least that
 // of an uncollapsed string value.
 // If the buffer is too small, the code will simply not compile.
-constexpr auto buffer_size = R"(with ""quote inside)"sv.size();  // uncollapsed size
+constexpr auto buffer_size = matrix[0][1].getRequiredBufferSize();  // uncollapsed size
 constexpr auto buffer = matrix[0][1].getCleanStringBuffer<buffer_size>();
 static_assert(buffer.getStringView() == R"(with "quote inside)"sv);
 ```

csv_parser/csv_cell.h

@@ -238,10 +238,11 @@ class CellStringReference {
 		/// Reserving additional character for terminating null is not required.
 		/// \return invalid buffer if BufferSize is too small.
 		template<std::size_t BufferSize>
-		[[nodiscard]] constexpr CellStringBuffer<BufferSize> getCleanStringBuffer() const
-		{
-			return CellStringBuffer<BufferSize>(value_, has_escaped_quotes_);
-		}
+		[[nodiscard]] constexpr CellStringBuffer<BufferSize> getCleanStringBuffer() const;
+
+		/// Get required buffer size to use as getCleanStringBuffer()'s template argument.
+		/// This function is useful in constexpr context.
+		[[nodiscard]] constexpr std::size_t getRequiredBufferSize() const;
 
 
 	private:
@@ -582,6 +583,21 @@ std::string CellStringReference::getCleanString()
 
 
 
+template<std::size_t BufferSize>
+constexpr CellStringBuffer<BufferSize> CellStringReference::getCleanStringBuffer() const
+{
+	return CellStringBuffer<BufferSize>(value_, has_escaped_quotes_);
+}
+
+
+
+constexpr std::size_t CellStringReference::getRequiredBufferSize() const
+{
+	return value_.size();
+}
+
+
+
 
 
 CellStringValue::CellStringValue(std::string_view cell, CellTypeHint hint)

examples/example_compiletime.cpp

@@ -35,6 +35,14 @@ NaN, -Inf
 	static_assert(matrix[0][2].getOriginalStringView() == "NaN"sv);
 	static_assert(matrix[1][2].getOriginalStringView() == " -Inf"sv);
 
+	// To support consecutive double-quote collapsing at compile-time, allocate a compile-time
+	// buffer to place the clean string inside. The buffer size has to be at least that
+	// of an uncollapsed string value.
+	// If the buffer is too small, the code will simply not compile.
+	constexpr auto buffer_size = matrix[1][1].getRequiredBufferSize();  // uncollapsed size
+	constexpr auto buffer = matrix[1][1].getCleanStringBuffer<buffer_size>();
+	static_assert(buffer.getStringView() == R"(with "quote inside)"sv);
+
 	return EXIT_SUCCESS;
 }
 

examples/readme_examples.cpp

@@ -123,7 +123,7 @@ License: 0BSD (Zero-Clause BSD)
 	// buffer to place the clean string inside. The buffer size has to be at least that
 	// of an uncollapsed string value.
 	// If the buffer is too small, the code will simply not compile.
-	constexpr auto buffer_size = R"(with ""quote inside)"sv.size();  // uncollapsed size
+	constexpr auto buffer_size = matrix[0][1].getRequiredBufferSize();  // uncollapsed size
 	constexpr auto buffer = matrix[0][1].getCleanStringBuffer<buffer_size>();
 	static_assert(buffer.getStringView() == R"(with "quote inside)"sv);
 }

tests/test_csv_parser.cpp

@@ -402,11 +402,24 @@ R"(abc, "def"
 		static_assert(matrix[0][1].getOriginalStringView() == R"(with ""quote inside)"sv);
 		static_assert(matrix[1][1].getOriginalStringView() == "6"sv);
 
-		constexpr auto buffer_size = R"(with ""quote inside)"sv.size();
-		constexpr auto buffer = matrix[0][1].getCleanStringBuffer<buffer_size>();
-		static_assert(buffer.getStringView() == R"(with "quote inside)"sv);
-		static_assert(buffer.isValid());
-		static_assert(buffer.getOptionalStringView().has_value());
+		{
+			// constexpr auto buffer_size = R"(with ""quote inside)"sv.size();
+			constexpr auto buffer_size = matrix[0][1].getRequiredBufferSize();
+			static_assert(buffer_size == 19);
+
+			constexpr auto buffer = matrix[0][1].getCleanStringBuffer<buffer_size>();
+			static_assert(buffer.getStringView() == R"(with "quote inside)"sv);
+			static_assert(buffer.isValid());
+			static_assert(buffer.getOptionalStringView().has_value());
+		}
+
+		{
+			constexpr auto buffer_size = 1024;  // large buffer size
+			constexpr auto buffer = matrix[0][1].getCleanStringBuffer<buffer_size>();
+			static_assert(buffer.getStringView() == R"(with "quote inside)"sv);
+			static_assert(buffer.isValid());
+			static_assert(buffer.getOptionalStringView().has_value());
+		}
 
 		// These will fail to compile due to small buffer size
 		// constexpr auto small_buffer_size = "with \"\"quote inside"sv.size() - 1;