An implicit conversion in the source type is defined by a type conversion operator named after the destination type (e.g. operator bool()). An implicit conversion in the destination type is defined by a default values. The explicit keyword can be applied to a constructor or (since C++11) a conversion operator, to ensure that it can only be used when the destination type is explicit at the point of use, e user- defined types, the copy behavior is defined by the copy constructor and the copy-assignment operator. string is an example of a copyable type. A movable type is one that can be initialized and assigned

prefer to break at a higher syntactic level. Also: 1. When a line is broken at a non-assignment operator the break comes before the symbol. (Note that this is not the same practice used in Google style style for other languages, such as C++ and JavaScript.) • This also applies to the following “operator-like” symbols: the dot separator (.), the two colons of a method reference (::), the amper- sand in type When a line is broken at an assignment operator the break typically comes after the symbol, but either way is acceptable. • This also applies to the “assignment-operator-like” colon in an en- hanced for (“foreach”)

common operations like multiplication, use the functions from the operator module instead of lambda functions. For example, prefer operator.mul to lambda x, y: x * y. Conditional Expressions link￿ Okay the @property decorator - see below). Must inherit from object. Can hide side-effects much like operator overloading. Can be confusing for subclasses. Decision: Use properties in new code to access or around arithmetic operators but always be consistent about whitespace on either side of a binary operator. Yes: x == 1 No: x<1 Don’t use spaces around the ‘=’ sign when used to indicate a keyword argument

-XX:-DontCompileHugeMethods Presentation – Result Interpretation [Matthias Boehm et al: On Optimizing Operator Fusion Plans for Large-Scale Machine Learning in SystemML. PVLDB 11(12) 2018] 19 706.015 Introduction

Afraid to Ask. PVLDB 11(13) 2018  #15.2 Prashanth Menon, Andrew Pavlo, Todd C. Mowry: Relaxed Operator Fusion for In- Memory Databases: Making Compilation, Vectorization, and Prefetching Work Together