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#include "kapi/cio.hpp"
#include <optional>
#include <string_view>
#include <utility>
namespace kapi::cio
{
namespace
{
struct null_device final : public output_device
{
null_device static instance;
auto write(output_stream, std::string_view) -> void override {}
};
constinit null_device null_device::instance;
} // namespace
constinit auto static active_device = static_cast<output_device *>(&null_device::instance);
auto set_output_device(output_device & device) -> std::optional<output_device *>
{
if (&device == active_device)
{
return {};
}
return std::exchange(active_device, &device);
}
auto write(output_stream stream, std::string_view text) -> void
{
active_device->write(stream, text);
}
} // namespace kapi::cio
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