c - Checking enum values at compile time -

i'd check static initalizers @ compile time. i'm implementing macro cassert() this question.

now, have "strange" situation

typedef enum {     eqadc_chan_a_00 = 0,     eqadc_chan_a_01,     eqadc_chan_a_02,     eqadc_chan_a_03,     eqadc_chan_a_04,     ...                 // others     eqadc_chan_max      // eqadc_chan_max = 62  } eqadc_tinputbiosid; 

and have structure initialized this:

const t_eqadc_pin_config eqadc_xpinconfig[eqadc_chan_max] = {     { 123 },  /* eqadc_chan_a_00 */     { 321 },  /* eqadc_chan_a_01 */     ...       /* others */ }; 

what strange (to me...) following statement

cassert(( sizeof(eqadc_xpinconfig)/sizeof(eqadc_xpinconfig[0]) ) != 62 ); 

works fine, , "passes" (i.e. compiles without errors). instead, this:

cassert(( sizeof(eqadc_xpinconfig)/sizeof(eqadc_xpinconfig[0]) ) != eqadc_chan_max ); 

does not (i.e. generates assertion, , stops compiler.

trying figure out why happens, think problem related value of eqadc_chan_max, not known @ compile time, being enum value. if case, still can't understand why declaration

const t_eqadc_pin_config eqadc_xpinconfig[eqadc_chan_max] 

actually instantiates correct size array... on how can (better) implement appreciated.

edit: fault. correct syntax is

cassert(( sizeof(eqadc_xpinconfig)/sizeof(eqadc_xpinconfig[0]) ) == eqadc_chan_max ); 

furthermore, pay attention declaring array way:

const t_eqadc_pin_config eqadc_xpinconfig[eqadc_chan_max] = { initializers ....} 

actually allocates size of eqadc_chan_max elements, if number of initialized elements not correct. so, right way implement is:

const t_eqadc_pin_config eqadc_xpinconfig[] = { initializers ....} cassert(( sizeof(eqadc_xpinconfig)/sizeof(eqadc_xpinconfig[0]) ) == eqadc_chan_max ); 

thank all.

have @ this thread.

if doesn't can run compilation step -p option, or whatever compiler, produce pre-processor output? might clarify why predicate in 2nd assertion doesn't evaluate expect.

also, why asserting size of array not 62?