#wierd cpp syntax leading to error

38 messages · Page 1 of 1 (latest)

thin ferry
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while working on the project there was this error on the main saying Inline function 'MEU::apply_texture' is not defined
main.cpp

#include "helper.hpp"
...

int main() {
  ...

  MEU::apply_texture(viewport, 8*4, image_size); // error
...

helper.hpp

namespace MEU {
...

constexpr void apply_texture(sf::VertexArray& arr,
                             const uint32_t vertex_ammount,
                             const sf::Vector2f texture_size);
...
fading coralBOT
#

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light marlin
thin ferry
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its the error from the linter

light marlin
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try to compile

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see what the compiler gives you

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linter can mess up at times

opaque sequoia
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A constexpr function is implicitly inline, so you need to define it in the header.

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It looks like you have only a declaration there.

light marlin
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oh... you're right

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Didn't see the ;

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thought the definition was ommited

thin ferry
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wait so i have to define it on the header?

light marlin
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Yeah

thin ferry
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thats wierd.....

light marlin
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As stabile said, it's inline inherently

opaque sequoia
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how should constexpr work if there is no definition of the function visible to the compiler?

light marlin
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So yeah, you can't split the declaration/definition

thin ferry
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thanks

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!solves

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!solved

fading coralBOT
#

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opaque sequoia
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btw. do you expect constexpr to actually do anything here? what texture are you going to apply at compile-time?

thin ferry
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idk....

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im super new on cpp

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and compiled languages

opaque sequoia
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why did you write constexpr then?

thin ferry
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idk.... maybe because i see other people do that

opaque sequoia
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then I'd suggest just not adding things that you don't know what they do and get rid of constexpr, instead of moving the definition to the header

thin ferry
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Well most of the usage of that function, all of it's parameters was known on compile time....

opaque sequoia
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If it actually makes sense for the function to be evaluated during compilation, then sure, add constexpr and move the definition to the header. But from what I can see that doesn't look likely.

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Do sf::VertexArray and sf::Vector2f even have constexpr support?

light marlin
thin ferry
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What does that mean....

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How do I know if a function is runtime or compile time

light marlin
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When you define something as constexpr it means that everything that it does can be done at compiletime

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Take something like sqrt

light marlin