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#include "kapi/cio.hpp"
#include <optional>
#include <string_view>
#include <utility>
namespace teachos::cio
{
namespace
{
struct null_device final : public output_device
{
null_device static instance;
auto write(std::string_view) -> void override {}
auto writeln(std::string_view) -> void override {}
auto write_error(std::string_view) -> void override {}
auto writeln_error(std::string_view) -> void override {}
};
constinit null_device null_device::instance;
} // namespace
// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
constinit auto 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 print(std::string_view text) -> void
{
active_device->write(text);
}
auto println(std::string_view text) -> void
{
active_device->writeln(text);
}
auto print_error(std::string_view text) -> void
{
active_device->write_error(text);
}
auto println_error(std::string_view text) -> void
{
active_device->writeln_error(text);
}
} // namespace teachos::cio
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