Function scan

Source/external/json.hpp:8810–8896

	}

	token_type scan()
	{
		// initially, skip the BOM
		if (position.chars_read_total == 0 && !skip_bom())
		{
			error_message = "invalid BOM; must be 0xEF 0xBB 0xBF if given";
			return token_type::parse_error;
		}

		// read next character and ignore whitespace
		skip_whitespace();

		// ignore comments
		while (ignore_comments && current == '/')
		{
			if (!scan_comment())
			{
				return token_type::parse_error;
			}

			// skip following whitespace
			skip_whitespace();
		}

		switch (current)
		{
			// structural characters
			case '[':
				return token_type::begin_array;
			case ']':
				return token_type::end_array;
			case '{':
				return token_type::begin_object;
			case '}':
				return token_type::end_object;
			case ':':
				return token_type::name_separator;
			case ',':
				return token_type::value_separator;

			// literals
			case 't':
			{
				std::array<char_type, 4> true_literal = {{static_cast<char_type>('t'), static_cast<char_type>('r'), static_cast<char_type>('u'), static_cast<char_type>('e')}};
				return scan_literal(true_literal.data(), true_literal.size(), token_type::literal_true);
			}
			case 'f':
			{
				std::array<char_type, 5> false_literal = {{static_cast<char_type>('f'), static_cast<char_type>('a'), static_cast<char_type>('l'), static_cast<char_type>('s'), static_cast<char_type>('e')}};
				return scan_literal(false_literal.data(), false_literal.size(), token_type::literal_false);
			}
			case 'n':
			{
				std::array<char_type, 4> null_literal = {{static_cast<char_type>('n'), static_cast<char_type>('u'), static_cast<char_type>('l'), static_cast<char_type>('l')}};
				return scan_literal(null_literal.data(), null_literal.size(), token_type::literal_null);
			}

			// string