Exercise: `RandomSensor_nopoly` (Non-Polymorphic)¶

Requirement ¶

Implement a sensor class RandomSensor_nopoly which does not access any real hardware, but rather returns a random temperature within a given range.

Download sensor-random-nopoly-basic.cpp¶

#include <gtest/gtest.h>
#include <sensor-random-nopoly.h>

TEST(sensor_random_suite, basic)
{
    RandomSensor_nopoly rs(36.4, 42.3);                // <--- give measurements between lo and hi

    double t = rs.get_temperature();
    ASSERT_GE(t, 36.4);                                // <--- greater equal to lo
    ASSERT_LE(t, 42.3);                                // <--- less equal to hi

    ASSERT_FLOAT_EQ(rs.low(), 36.4);                   // <--- RandomSensor specific interface
    ASSERT_FLOAT_EQ(rs.high(), 42.3);                  // <--- RandomSensor specific interface
}

Implementation Hint: Randomicity In C++¶

The following program demonstrates how to generate uniformly distributed random double values in a specified range.

Download random-demo.cpp¶

#include <random>
#include <iostream>

int main()
{
    // setup how we want our random numbers to be created (think:
    // object initialization)
    double lo = 36.1;
    double hi = 42.7;

    // object state. think: what does the object need during runtime?
    std::random_device rd;                                       // <--- /dev/random, used to obtain a seed
    std::default_random_engine engine(rd());                     // <--- init (and seed) RNG
    std::uniform_real_distribution<double> distribution(lo, hi); // <--- tailor desired distribution

    // draw 10 random numbers (think: measure temperature)
    for (int i=0; i<10; i++) {
        double number = distribution(engine);                    // <--- use uniform_real_distribution to 
                                                                 //      draw a number from engine
                                                                 //      and bend it to desired range
                                                                 
        std::cout << number << std::endl;
    }

    return 0;
}

Implementation Hint: Initializer Lists ¶

See Constructors: Member Initialization for how to initialize members in an initializer list.

Topics Covered ¶