It's not possible to build (or rather use) libfort as .dll on windows

[invy]

Because of following externs:

libfort/src/fort.h

Lines 716 to 730 in 51910b1

	extern const struct ft_border_style *const FT_BASIC_STYLE;
	extern const struct ft_border_style *const FT_BASIC2_STYLE;
	extern const struct ft_border_style *const FT_SIMPLE_STYLE;
	extern const struct ft_border_style *const FT_PLAIN_STYLE;
	extern const struct ft_border_style *const FT_DOT_STYLE;
	extern const struct ft_border_style *const FT_EMPTY_STYLE;
	extern const struct ft_border_style *const FT_EMPTY2_STYLE;
	extern const struct ft_border_style *const FT_SOLID_STYLE;
	extern const struct ft_border_style *const FT_SOLID_ROUND_STYLE;
	extern const struct ft_border_style *const FT_NICE_STYLE;
	extern const struct ft_border_style *const FT_DOUBLE_STYLE;
	extern const struct ft_border_style *const FT_DOUBLE2_STYLE;
	extern const struct ft_border_style *const FT_BOLD_STYLE;
	extern const struct ft_border_style *const FT_BOLD2_STYLE;
	extern const struct ft_border_style *const FT_FRAME_STYLE;

it's not possible to use library as a .dll

please add corresponding macros for windows with __declspec(dllimport)/__declspec(dllexport).

IMHO it would be better to use enum and resolve it internally into a pointer to a built in style.