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_Static_assert(expression,message) | (since C11)(deprecated in C23) | ||||||||
static_assert(expression,message) | (since C23) | ||||||||
_Static_assert(expression) | (since C23)(deprecated in C23) | ||||||||
static_assert(expression) | (since C23) | ||||||||
| expression | - | anyinteger constant expression |
| message | - | anystring literal |
This keyword is also available as convenience macrostatic_assert, available in the header<assert.h>. | (until C23) |
Both of An implementation may also define | (since C23) |
The constant expression is evaluated at compile time and compared to zero. If it compares equal to zero, a compile-time error occurs and the compilermust displaymessage as part of the error message (except that characters not inbasic character set are not required to be displayed)(until C23)should displaymessage (if provided) as part of the error message(since C23).
Otherwise, ifexpression does not equal zero, nothing happens; no code is emitted.
#include <assert.h> // no longer needed since C23 int main(void){// Test if math works, C23: static_assert((2+2)%3==1,"Whoa dude, you knew!");// Pre-C23 alternative: _Static_assert(2+2*2==6,"Lucky guess!?"); // This will produce an error at compile time.// static_assert(sizeof(int) < sizeof(char), "Unmet condition!"); constexprint _42=2*3*2*3+2*3; static_assert(_42==42);// the message string can be omitted. // const int _13 = 13;// Compile time error - not an integer constant expression:// static_assert(_13 == 13);}
| aborts the program if the user-specified condition is nottrue. May be disabled for release builds (function macro)[edit] | |
C++ documentation for static_assert declaration | |
