Back to Basics Lambda Expressions Barbara Geller & Ansel Sermersheim CppCon September 2020Introduction ● Prologue ● History ● Function Pointer ● Function Object ● Definition of a Lambda Expression slot library ○ CsLibGuarded ■ library for managing access to data shared between threadsLambda Expressions ● History ○ lambda calculus is a branch of mathematics ■ introduced in the 1930’s to prove memory ■ languages which were influenced by lambda calculus ● Haskell, LISP, and ML 5Lambda Expressions ● History ○ why do we use the terminology lambda expression ■ greek letter λ refers to an anonymous

About me 2 6 ways for implementing math expressions calculator, Amir Kirsh Lecturer Academic College of Tel-Aviv-Yaffo and Tel-Aviv University Developer Advocate at Member of the Israeli ISO C++ NB NB Co-Organizer of the CoreCpp conference and meetup group3 6 ways for implementing math expressions calculator, Amir Kirsh Suffering from slow builds? It’s not just waste of time It affects your dev implementing math expressions calculator, Amir KirshSuccess Stories 5 6 ways for implementing math expressions calculator, Amir KirshSuccess Stories 6 6 ways for implementing math expressions calculator, Amir

expression doesn’t introduce an extra level of optionality to expressions that already return optionals. Large integer literal initialization expressions are inferred to be of the correct integer type. For example teamScore += 1 8 } 9 } 10 print(teamScore) 11 // Prints "11" In an if statement, the conditional must be a Boolean expression— this means that code such as if score { ... } is an error, not an clause that sets a different greeting if optionalName is nil. If the optional value is nil, the conditional is false and the code in braces is skipped. Otherwise, the optional value is unwrapped and assigned

. . . . . . . . . . . . 19 1.2.12 $ELSE : Switch conditional compilation . . . . . . . . . . . . . . . . . . . 19 1.2.13 $ELSEC : Switch conditional compilation . . . . . . . . . . . . . . . . . . . $ELIFC : Switch conditional compilation . . . . . . . . . . . 20 1.2.15 $ENDC : End conditional compilation . . . . . . . . . . . . . . . . . . . . . 20 1.2.16 $ENDIF : End conditional compilation . . . . . . . . . . . . . 23 1.2.29 $IF : Start conditional compilation . . . . . . . . . . . . . . . . . . . . . . 23 1.2.30 $IFC : Start conditional compilation . . . . . . . . . . . . . . . . . .

the configuration file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 5.2.1 Conditional processing of the config file . . . . . . . . . . . . . . . . . . . . 36 5.2.2 #CFGDIR . . . opened. • p : Write parse tree (tree.log) • q : Show message numbers. • c : Notify on each conditional being processed. • mxxx : xxx is a comma-separated list of messages numbers which should not be Generate profiler code for gprof. This will define the symbol FPC_PROFILE, which can be used in conditional defines. 30 CHAPTER 5. COMPILER CONFIGURATION -PB Show default Target CPU compiler binary -PP

6 } else { 7 teamScore += 1 8 } 9 } 10 teamScore In an if statement, the conditional must be a Boolean expression—this means that code such as if score { ... } is an error, not an clause that sets a different greeting if optionalName is nil. If the optional value is nil, the conditional is false and the code in braces is skipped. Otherwise, the optional value is unwrapped and assigned appropriate-sized number type (such as UInt8 in the example above) and can therefore be used in expressions alongside other values of the same type. ​ Int In most cases, you don’t need to pick a specific

in type contexts. Indexed Access Types Using Type['a'] syntax to access a subset of a type. Conditional Types Create types which act like if statements in the type system. Mapped Types Generating types types, it overlays type analysis on JavaScript's runtime control flow constructs like if/else , conditional ternaries, loops, truthiness checks, etc., which can all affect those types. Within our if check functions can be called. Let's learn about how to write types that describe functions. Function Type Expressions The simplest way to describe a function is with a function type expression. These types are syntactically

RewriteRule to simplify common rewriting scenarios. Adds the possibility to use complex boolean expressions in RewriteCond. Allows the use of SQL queries as RewriteMap functions. mod_ldap, mod_authnz_ldap allow httpd to build against your installed copy of APR and APR-Util. Perl-Compatible Regular Expressions Library (PCRE) This library is required but not longer bundled with httpd. Download the source Otherwise, httpd must be recompiled to add or remove modules. Configuration directives may be included conditional on a presence of a particular module by enclosing them in an block. However,

RewriteRule to simplify common rewriting scenarios. Adds the possibility to use complex boolean expressions in RewriteCond. Allows the use of SQL queries as RewriteMap functions. mod_ldap, mod_authnz_ldap allow httpd to build against your installed copy of APR and APR-Util. Perl-Compatible Regular Expressions Library (PCRE) This library is required but not longer bundled with httpd. Download the source Otherwise, httpd must be recompiled to add or remove modules. Configuration directives may be included conditional on a presence of a particular module by enclosing them in an block. However,

RewriteRule to simplify common rewriting scenarios. Adds the possibility to use complex boolean expressions in RewriteCond. Allows the use of SQL queries as RewriteMap functions. mod_ldap, mod_authnz_ldap allow httpd to build against your installed copy of APR and APR-Util. Perl-Compatible Regular Expressions Library (PCRE) This library is required but not longer bundled with httpd. Download the source Otherwise, httpd must be recompiled to add or remove modules. Configuration directives may be included conditional on a presence of a particular module by enclosing them in an block. However,