$ cat xyz.c
#include <stdio.h>
#include <string.h>

enum
{
        TOP_LEFT,
        TOP_RIGHT,
        BOTTOM_LEFT,
        BOTTOM_RIGHT,
        HORIZONTAL,
        VERTICAL,
        VERTICAL_LEFT,
        VERTICAL_RIGHT,
        TOP_DOWN,
        BOTTOM_UP,
        CROSS
};

char *glyphs[] =
{
        [TOP_LEFT]       = u8"┏",
        [TOP_RIGHT]      = u8"┓",
        [BOTTOM_LEFT]    = u8"┗",
        [BOTTOM_RIGHT]   = u8"┛",
        [HORIZONTAL]     = u8"━",
        [VERTICAL]       = u8"┃",
        [VERTICAL_LEFT]  = u8"┣",
        [VERTICAL_RIGHT] = u8"┫",
        [TOP_DOWN]       = u8"┳",
        [BOTTOM_UP]      = u8"┻",
        [CROSS]          = u8"╋"
};

int main()
{
        printf("sizeof(glyphs): %d\n", sizeof(glyphs));
        printf("glyph count:    %d\n\n", sizeof(glyphs) / sizeof(char *));

        for (size_t index = 0; index <= CROSS; index++)
        {
                printf("glyphs[%02d] = '%s'\n", index, glyphs[index]);
        }

        return 0;
}

$ cc -o xyz xyz.c -std=c11
$ ./xyz
sizeof(glyphs): 44
glyph count:    11

glyphs[00] = '┏'
glyphs[01] = '┓'
glyphs[02] = '┗'
glyphs[03] = '┛'
glyphs[04] = '━'
glyphs[05] = '┃'
glyphs[06] = '┣'
glyphs[07] = '┫'
glyphs[08] = '┳'
glyphs[09] = '┻'
glyphs[10] = '╋'