Formatter flag to force multi-line arrays (#282)

3 files changed, 14 insertions, 4 deletions

diff --git a/include/toml++/impl/formatter.hpp b/include/toml++/impl/formatter.hpp
index 0c97833f29..65005b124e 100644
--- a/include/toml++/impl/formatter.hpp
+++ b/include/toml++/impl/formatter.hpp
@@ -130,6 +130,12 @@ TOML_IMPL_NAMESPACE_START
 			return !!(config_.flags & format_flags::terse_key_value_pairs);
 		}
 
+		TOML_PURE_INLINE_GETTER
+		bool force_multiline_arrays() const noexcept
+		{
+			return !!(config_.flags & format_flags::force_multiline_arrays);
+		}
+
 		TOML_EXPORTED_MEMBER_FUNCTION
 		void attach(std::ostream& stream) noexcept;
 
diff --git a/include/toml++/impl/forward_declarations.hpp b/include/toml++/impl/forward_declarations.hpp
index 386a9e0688..f4dfe4ffd2 100644
--- a/include/toml++/impl/forward_declarations.hpp
+++ b/include/toml++/impl/forward_declarations.hpp
@@ -343,6 +343,9 @@ TOML_NAMESPACE_START // abi namespace
 
 		/// \brief Avoids the use of whitespace around key-value pairs.
 		terse_key_value_pairs = (1ull << 12),
+
+		/// \brief Always print multiline arrays (one element per line).
+		force_multiline_arrays = (1ull << 13),
 	};
 	TOML_MAKE_FLAGS(format_flags);
 
diff --git a/include/toml++/impl/toml_formatter.inl b/include/toml++/impl/toml_formatter.inl
index 8b4f633dca..bc8303248b 100644
--- a/include/toml++/impl/toml_formatter.inl
+++ b/include/toml++/impl/toml_formatter.inl
@@ -179,10 +179,11 @@ TOML_NAMESPACE_START
 		}
 
 		const auto original_indent = indent();
-		const auto multiline	   = TOML_ANON_NAMESPACE::toml_formatter_forces_multiline(
-			  arr,
-			  120u,
-			  indent_columns() * static_cast<size_t>(original_indent < 0 ? 0 : original_indent));
+		const auto multiline	   = force_multiline_arrays()
+							|| TOML_ANON_NAMESPACE::toml_formatter_forces_multiline(
+								   arr,
+								   120u,
+								   indent_columns() * static_cast<size_t>(original_indent < 0 ? 0 : original_indent));
 
 		print_unformatted("["sv);