Switch Enum to Only Non-Negative Values, Update Comments

lib/compress/zstd_compress.c

@@ -413,11 +413,8 @@ size_t ZSTD_CCtxParam_setParameter(
         return CCtxParams->forceWindow;
 
     case ZSTD_p_forceAttachDict : {
-        int signed_val = (int)value;
-        CCtxParams->attachDictPref = signed_val ?
-                                    (signed_val > 0 ? ZSTD_dictForceAttach :
-                                                      ZSTD_dictForceCopy) :
-                                     ZSTD_dictDefaultAttach;
+        CLAMPCHECK(value, ZSTD_dictDefaultAttach, ZSTD_dictForceCopy);
+        CCtxParams->attachDictPref = value;
         return CCtxParams->attachDictPref;
     }
 

lib/compress/zstd_compress_internal.h

@@ -48,12 +48,6 @@ extern "C" {
 typedef enum { ZSTDcs_created=0, ZSTDcs_init, ZSTDcs_ongoing, ZSTDcs_ending } ZSTD_compressionStage_e;
 typedef enum { zcss_init=0, zcss_load, zcss_flush } ZSTD_cStreamStage;
 
-typedef enum {
-    ZSTD_dictDefaultAttach = 0,
-    ZSTD_dictForceAttach = 1,
-    ZSTD_dictForceCopy = -1,
-} ZSTD_dictAttachPref_e;
-
 typedef struct ZSTD_prefixDict_s {
     const void* dict;
     size_t dictSize;