yorel::yomm2::policy::basic_trace_output
defined in <yorel/yomm2/policy.hpp>, also provided by <yorel/yomm2/core.hpp>, <yorel/yomm2/keywords.hpp>
template<class Policy, typename Stream = /*unspecified*/>
struct basic_trace_output;
basic_trace_output implements the trace_output facet.
Policy: the policy containing the facet. Since basic_trace_output has
static state, making the policy a template parameter ensures that each policy
has its own set of static member variables.
Stream: - Stream can be any type that satisfies the requirements of
RestrictedOutputStream. The default value is a lightweight version of
std::ostream that writes to stderr, using low-level C functions.
| Name | Value |
|---|---|
| bool trace_enabled | enable or disable trace |
| Stream trace_stream | the stream to print to |
Controls whether information is printed to trace_stream. The flag is
initialized by examining the YOMM2_TRACE environment variable. If it is set,
and its value is 1, trace is enabled. Other values are reserved for possible
future use.
Initialized by the default constructor of Stream. It is the responsibility of
the program to perform further initialization if needed - for example, open a
std::ofstream, before calling update.