function::user_ulong_warn - Linux
Overview
function::user_ulong_warn is a constructor that builds a warning handler function that converts an unsigned 64-bit integer to a warning
Syntax
namespace function {
bool user_ulong_warn(warning warner, int line, string const& spec, unsigned long long val);
}
The following parameters are accepted:
- warner: A suitable predicate function that is ‘true’ when a warning should be issued
- line: Line number of the code where the function is called.
- spec: Format specification string for the
val
argument (seeprintf(3)
). - val: Variable to be dumped in accordance with the format specification
spec
Options/Flags
None.
Examples
The following code sample shows you how to use the function::user_ulong_warn function:
void f() {
auto const& warner = function::user_julong_warn;
warner(false, __LINE__, "%lld", 42ull); // no warning
warner(true, __LINE__, "%lld", 42ull); // warning: 42
}
Common Issues
None.
Integration
This function can be used in conjunction with the function::user_julong_info
and function::user_julong_err
functions to cover most logging needs.