I'm trying to do a simple union type in nim as such:
type SeqLike[T] = ptr UncheckedArray[T] | seq[T]
proc getFirst[T](list: SeqLike[T]): T =
list[0]
proc main() =
let test1 = @[1, 2, 3, 4, 5]
let test2 = @['1', '2', '3', '4', '5']
let test3 = cast[ptr UncheckedArray[int]]( addr(test1[0]) )
let test4 = cast[ptr UncheckedArray[char]]( addr(test2[0]) )
echo "test1"
echo getFirst(test1)
echo "test2"
echo getFirst(test2)
echo "test3"
echo getFirst(test3)
echo "test4"
echo getFirst(test4)
if isMainModule:
main()When I try to compile this file (test.nim) I get the following error:
CC: [redacted]/Nim/nim-2.2.0/lib/system.nim
CC: test.nim
C:\[redacted]\nimcache\test_d\@mtest.nim.c: In function 'main__test_u7':
C:\[redacted]\nimcache\test_d\@mtest.nim.c:206:34: error: incompatible type for argument 1 of 'getFirst__test_u20'
206 | T7_ = getFirst__test_u20(test3);
| ^~~~~
| |
| NI * {aka long long int *}
C:\[redacted]\nimcache\test_d\@mtest.nim.c:120:84: note: expected 'tySequence__qwqHTkRvwhrRyENtudHQ7g' but argument is of type 'NI *' {aka 'long long int *'}
120 | N_LIB_PRIVATE N_NIMCALL(NI, getFirst__test_u20)(tySequence__qwqHTkRvwhrRyENtudHQ7g list_p0) {
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
C:\[redacted]\nimcache\test_d\@mtest.nim.c:214:34: error: incompatible type for argument 1 of 'getFirst__test_u24'
214 | T9_ = getFirst__test_u24(test4);
| ^~~~~
| |
| NIM_CHAR * {aka char *}
C:\[redacted]\nimcache\test_d\@mtest.nim.c:130:91: note: expected 'tySequence__lBgZ7a89beZGYPl8PiANMTA' but argument is of type 'NIM_CHAR *' {aka 'char *'}
130 | N_LIB_PRIVATE N_NIMCALL(NIM_CHAR, getFirst__test_u24)(tySequence__lBgZ7a89beZGYPl8PiANMTA list_p0) {
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
Error: execution of an external compiler program 'C:\[redacted]\Nim\nim-2.2.0\dist\mingw64\bin\gcc.exe -c -w -fmax-errors=3 -mno-ms-bitfields -IC:\[redacted]\Nim\nim-2.2.0\lib -Ic:\[redacted] -o C:\[redacted]\nimcache\test_d\@mtest.nim.c.o C:\[redacted]\nimcache\test_d\@mtest.nim.c' failed with exit code: 1Cheers!