ece150: add exceptions and classes 2

docs/ce1/ece150.md

@@ -488,3 +488,72 @@ Namespaces can also be nested within namespaces.
     `std::cout` does weird shenanigans that passes itself to every function afterward, such as `std::endl`.
     
     This means that `std::cout << std::endl;` is equivalent to `std::endl(std::cout);`.
+    
+### Operator overloading
+
+Operators can be overloaded for various classes.
+
+!!! example
+    Overloading for displaying to `cout`:
+    
+    ```cpp
+    std::ostream operator<<(std::ostream &out, ClassName const &p) {
+    	out << "text here";
+    	return out;
+    }
+
+
+### Constructors
+
+Constructors can be defined with default values after a colon and before the function body:
+
+```cpp
+Rational::Rational():
+  numer_{0},
+  denom_{0} {
+}
+```
+
+Subsequent members can even use the values of previous ones.
+
+Constructors can also contain parameters with default values, but default values must also be present in the class declaration.
+
+### Member functions
+
+A `const` after a member function forbids the modification of any member variables within that function.
+
+```cpp
+int get_val() const {
+}
+```
+
+## Exceptions
+
+`#define NDEBUG` turns off assertions.
+
+`static_cast<double>(var)` performs the typical implicit conversion explicitly during compile time.
+
+Exceptions are expensive error handlers that **do not protect** from program termination (e.g., attempt to access invalid memory).
+
+The following are all exception classes in `std`:
+
+- `domain_error`
+- `runtime_error`
+- `range_error`
+- `overflow_error`
+- `underflow_error`
+- `logic_error`
+- `length_error`
+- `out_of_range`
+
+`...` is a catch-all exception.
+
+!!! example
+    ```cpp
+    try {
+    	throw std::domain_error{"cannot compute stupidity"};
+    } catch (std::domain_error &e) {
+    	std::cerr << e->what();
+    } catch (...) {
+    }
+    ```