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---
# runtime_checks
Disables or restores the [/RTC](../build/reference/rtc-run-time-error-checks.md) settings.  
  
## Syntax  
  
```  
  
#pragma runtime_checks( "[runtime_checks]", {restore | off} )  
```  
  
## Remarks  
 You cannot enable a run-time check that was not enabled with a compiler option. For example, if you do not specify /RTCs, specifying `#pragma runtime_checks( "s", restore)` will not enable stack frame verification.  
  
 The **runtime_checks** pragma must appear outside a function and takes effect at the first function defined after the pragma is seen. The **restore** and **off** arguments turn options specified in the *runtime_checks* on or off.  
  
 The *runtime_checks* can be zero or more of the parameters shown in the following table.  
  
### Parameters of the runtime_checks Pragma  
  
|Parameter(s)|Type of run-time check|  
|--------------------|-----------------------------|  
|**s**|Enables stack (frame) verification.|  
|**c**|Reports when a value is assigned to a smaller data type that results in a data loss.|  
|**u**|Reports when a variable is used before it is defined.|  
  
 These are the same letters used with the /RTC compiler option. For example:  
  
```  
#pragma runtime_checks( "sc", restore )  
```  
  
 Using the **runtime_checks** pragma with the empty string (**""**) is a special form of the directive:  
  
-   When you use the **off** parameter, it turns the run-time error checks, listed in the table above, off.  
  
-   When you use the **restore** parameter, it resets the run-time error checks to those that you specified with the /RTC compiler option.  
  
```  
#pragma runtime_checks( "", off )  
.  
.  
.  
#pragma runtime_checks( "", restore )   
```  
  
## See Also  
 [Pragma Directives and the __Pragma Keyword](../preprocessor/pragma-directives-and-the-pragma-keyword.md)