Smart switch over TBuffer w/ C++-20 templated lambdas

example.cpp

#include <iostream>

struct CpuBuffer {};

struct CudaBuffer {};

template<typename TBuffer>
int getValue();

int cpuValue = 1;
int cudaValue = 2;

template<>
int getValue<CpuBuffer>() {
    return cpuValue;
}

template<>
int getValue<CudaBuffer>() {
    return cudaValue;
}

enum class DeviceType {
    kCpu,
    kCuda,
};


template <typename TVisitor>
auto smartSwitch(DeviceType dt, TVisitor visitor) {
    switch (dt) {
        case DeviceType::kCpu:
            return visitor.template operator()<CpuBuffer>();
        case DeviceType::kCuda:
            return visitor.template operator()<CudaBuffer>();
        default:
            throw std::runtime_error("");
    }
}

int main() {
    std::cout << smartSwitch(DeviceType::kCpu, []<typename TBuffer>(){ return getValue<TBuffer>(); }) << std::endl;
}