c++ - Why allow function declarations inside function bodies -

why syntax allow function declarations inside function bodies?

it create lot of questions here on function declarations mistaken variable initializations , like.

a object(); 

not mention vexing parse.

is there use-case not achieved more common scope hiding means namespaces , members?

is historical reasons?

addendum: if historical reasons, inherited c limit scope, problem banning them?

whilst many c++ applications written solely in c++ code, there lot of code mixture of c , c++ code. mixture of c++'s important part of usefulness (including "easy" interfacing existing api's, opengl or curl custom hardware drivers written in c, can pretty used directly little effort, trying interface custom hardware c driver basic interpreter pretty diffcult)

if start breaking compatibility removing things "for no particular value", c++ no longer useful. aside giving better error messages in condition confusing, of course useful in itself, it's hard see how it's useful remove - , that's of course assuming none of c++ using in - , wouldn't surprised if happen @ times in modern code (for whatever or bad reasons).

in general, c++ tries hard not break backwards compatibility - , this, in mind, thing. that's why keyword static used bunch of different things, rather adding new keyword, , auto means different used in c, it's not "new" keyword break existing code happened use whatever other word chosen (and small break, nobody used past 20 years anyway).