version 4.2.0

Added

• Support std::optional members for TOML11_DEFINE_CONVERSION_NON_INTRUSIVE (#260) (by Ken Matsui @ken-matsui)
• Make thread_local for color_mode optional (#259) (#261) (by Ken Matsui @ken-matsui)
• add usage with CPM to README
• add explanation about ordered_map to README and update doc

Fixed

• Manually cast file size to std::streamsize (#258) (by Pino Toscano @pinotree)
• Typographical error in table_format output
• Format an empty array specified as array-of-table in one line (#262)
• Added a missing include file (#263)
• Fix typos in documentation template syntax (#264) (by Jack W @jackwil1)
• Fix toml::find_or for deeply nested tables (#266)